A motorist drive past phosphate storage shed at the Dorowa mine in Hwedza, Zimbabwe October 22, 2019. REUTERS/Philimon Bulawayo

A worker is seen sampling packed phosphate at a packing warehouse at the Dorowa mine in Hwedza, Zimbabwe October 22, 2019. REUTERS/Philimon Bulawayo

A worker is seen sampling packaged phosphate at a packing warehouse at the Dorowa mine in Hwedza, Zimbabwe October 22, 2019. REUTERS/Philimon Bulawayo

A man passes under a conveyor belt that transports a treated phosphate to the chemical group in Mdhilla, Tunisia February 13, 2019. Picture taken February 13, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A bulldozer transports a treated phosphate to be put in wagons at a phosphate production plant in Metlaoui, Tunisia February 8, 2019. Picture taken February 8, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A worker reacts at a phosphate production plant at the end of his shift in Metlaoui, Tunisia February 8, 2019. Picture taken February 8, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

Vehicles transport an untreated phosphate at a phosphate production plant in Metlaoui, Tunisia February 8, 2019. Picture taken February 8, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A worker drives a bulldozer, transporting a treated phosphate to be put in wagons, at a phosphate production plant in Metlaoui, Tunisia February 8, 2019. Picture taken February 8, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A general view of the Metlaoui phosphate production plant in Metaloui, Tunisia February 8, 2019. Picture taken February 8, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A general view of the Metlaoui phosphate production plant in Metaloui, Tunisia February 8, 2019. Picture taken February 8, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A general view of the Metlaoui phosphate production plant in Metaloui, Tunisia February 8, 2019. Picture taken February 8, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A worker is seen at a phosphate production plant in Metlaoui, Tunisia February 8, 2019. Picture taken February 8, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A general view of the Mdhilla phosphate production plant in Mdhilla, Tunisia February 9, 2019. Picture taken February 9, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A general view of the Mdhilla phosphate production plant in Mdhilla, Tunisia February 9, 2019. Picture taken February 9, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A general view of the Mdhilla phosphate production plant in Mdhilla, Tunisia February 9, 2019. Picture taken February 9, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A bulldozer works at a phosphate factory in Mdhilla, Tunisia February 9, 2019. Picture taken February 9, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

Vehicles transport untreated phosphate at a phosphate mine in Mdhilla, Tunisia February 9, 2019. Picture taken February 9, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A vehicle transports untreated phosphate at a phosphate mine in Mdhilla, Tunisia February 9, 2019. Picture taken February 9, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

Boubaker Akremi, 37, who works at the state phosphate company CPG, drives his motorbike to work at a phosphate mine, in Mdhilla, Tunisia February 14, 2019. Picture taken February 14, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

Heavy machinery is seen at a phosphate mine in Mdhilla, Tunisia February 9, 2019. Picture taken February 9, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

Heavy machinery is seen at a phosphate mine in Mdhilla, Tunisia February 9, 2019. Picture taken February 9, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

Dynamite explosions blast rock mass at a phosphate mine in Mdhilla, Tunisia February 15, 2019. Picture taken February 15, 2019. TO MATCH INSIGHT TUNISIA-ECONOMY/ REUTERS/Zoubeir Souissi

A sign is seen for niobium and phosphate mining facilities owned by China Molybdenum Co Ltd (CMOC) in Catalao, Goias state, Brazil October 5, 2018. Picture taken October 5, 2018. REUTERS/Jake Spring

A sign is seen for niobium and phosphate mining facilities owned by China Molybdenum Co Ltd (CMOC) in Catalao, Goias state, Brazil October 5, 2018. Picture taken October 5, 2018. REUTERS/Jake Spring

A general view shows the phosphate mine in Umm al-arais, Tunisia February 15, 2018. Picture taken February 15, 2018.REUTERS/Zoubeir Souissi *** Local Caption *** A general view shows the phosphate mine in Umm al-arais

Protesters stand outside a tent near the entrance of the phosphate mine in Umm al-arais, Tunisia February 15, 2018. Picture taken February 15, 2018. REUTERS/Zoubeir Souissi *** Local Caption *** Protesters are seen near tents the entrance to the phosphate mine in Umm al-arais

The logo of Gafsa Phosphate Company is seen at the entrance to the mine in Umm al-arais, Tunisia February 15, 2018. Picture taken February 15, 2018.REUTERS/Zoubeir Souissi *** Local Caption *** The logo of Gafsa Phosphate Company is seen the entrance to the mine closed in Umm al-arais

Protesters sit outside a tent near the entrance of the phosphate mine in Umm al-arais, Tunisia February 15, 2018. Picture taken February 15, 2018. REUTERS/Zoubeir Souissi *** Local Caption *** Protesters are seen near tents the entrance to the phosphate mine in Umm al-arais

A general view shows the entrance of the phosphate mine in Umm al-arais, Tunisia February 15, 2018. Picture taken February 15, 2018. REUTERS/Zoubeir Souissi *** Local Caption *** A general view shows the entrance to the phosphate mine in Umm al-arais

Protesters sit in a tent near the entrance of the phosphate mine in Umm al-arais, Tunisia February 15, 2018. Picture taken February 15, 2018. REUTERS/Zoubeir Souissi *** Local Caption *** Protesters are seen near tents the entrance to the phosphate mine in Umm al-arais

Protesters sit outside a tent near the entrance of the phosphate mine in Umm al-arais, Tunisia February 15, 2018. Picture taken February 15, 2018. REUTERS/Zoubeir Souissi *** Local Caption *** Protesters are seen near tents the entrance to the phosphate mine in Umm al-arais

Carte de la Tunisie localisant les récentes manifestations ainsi que les installations abritant du phosphate, du gaz et du pétrole, menacées de blocage par les manifestants

Tunisia's President Beji Caid Essebsi on Wednesday ordered the army to protect phosphate, gas and oil production facilities after protests in the country.

At a rocky outpost in Western Sahara, a new generation of soldiers who have never known war are mobilising as tensions resurface in one of Africa's oldest disputes after a quarter century of uneasy peace. Young Sahrawi troops man new desert posts for the Polisario Front, which for more than 40 years has sought independence for the vast desert region - first in a guerrilla war against Morocco and then politically since a ceasefire deal in 1991. Now a standoff with Morocco, which controls the majority of Western Sahara, is renewing pressure for a diplomatic solution to ensure foot soldiers don't return to fighting as the last generation of commanders once did. The standoff since August has brought Moroccan and Polisario forces within 200 metres of each other in a narrow strip of land near the Mauritanian border. Rich in phosphate, Western Sahara has been contested since 1975 when Spanish colonial powers left. Morocco claimed the territory and fought the 16-year war with Polisario. REUTERS/ Zohra Bensemra SEARCH ÒPOLISARIOÓ FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY Matching text: WESTERNSAHARA-DISPUTE/

General view of wagons loaded with phosphate, during a blockade by protesters of the rail line to the Redayef mine, in Redayef ,Tunisia October 16, 2016. Picture taken October 16, 2016. To match Insight TUNISIA-POLITICS/ REUTERS/Zoubeir Souissi

Protesters are seen near a blockade against phosphate transported by rail from the Redayef mine, in Redayef, Tunisia October 17, 2016. Picture taken October 17, 2016. The graffiti reads, "Work" ''Freedom'' and "Dignity". To match Insight TUNISIA-POLITICS/ REUTERS/Zoubeir Souissi

People are seen near a blockade of phosphate transported by rail from the Redayef mine, in Redayef, Tunisia October 17, 2016. Picture taken October 17, 2016.The graffiti reads, ''No phosphate if not job ''. To match Insight TUNISIA-POLITICS/ REUTERS/Zoubeir Souissi

Protesters are seen near a train station during a blockade of phosphate transported by rail from the Redayef mine, in Redayef, Tunisia October 16, 2016. Picture taken October 16, 2016. To match Insight TUNISIA-POLITICS/ REUTERS/Zoubeir Souissi

Protesters are seen near a train station during a blockade of phosphate transported by rail from the Redayef mine, in Redayef, Tunisia October 16, 2016. Picture taken October 16, 2016. To match Insight TUNISIA-POLITICS/ REUTERS/Zoubeir Souissi

A view of train wagons loaded with phosphate, during a blockade by protesters that is halting transport by rail to Redayef mine, in Redayef, Tunisia October 16, 2016. Picture taken October 16, 2016. To match Insight TUNISIA-POLITICS/ REUTERS/Zoubeir Souissi

Protesters are seen near a train station during a blockade of phosphate transported by rail from the Redayef mine, in Redayef, Tunisia October 16, 2016. Picture taken October 16, 2016. To match Insight TUNISIA-POLITICS/ REUTERS/Zoubeir Souissi

Protesters are seen near a blockade against phosphate transported by rail from the Redayef mine, in Redayef ,Tunisia October 17, 2016. Picture taken October 17, 2016. The graffiti reads, "Work" ''Freedom''and "Dignity". To match Insight TUNISIA-POLITICS/ REUTERS/Zoubeir Souissi

A view of train wagons loaded with phosphate, during a blockade by protesters that is halting transport by rail to Redayef mine, in Redayef, Tunisia October 16, 2016. Picture taken October 16, 2016. To match Insight TUNISIA-POLITICS/ REUTERS/Zoubeir Souissi

Protesters are seen near a blockade against phosphate transported by rail from the Redayef mine, in Redayef ,Tunisia October 17, 2016. Picture taken October 17, 2016. To match Insight TUNISIA-POLITICS/ REUTERS/Zoubeir Souissi

Mike James, an employee of Mosaic Co, holds phosphate pebbles as it comes off the grading screens at Mosaic's South Fort Meade Mine in Fort Meade, Florida January 13, 2010. REUTERS/Scott Audette/File Photo

Heavy machinery is seen at a phosphate mine at Boucraa factory of the National Moroccan phosphate company (OCP) situated in the southern provinces, 100 km southwest of the town of Laayoune February 18, 2016. REUTERS/Youssef Boudlal

A vehicle carries untreated phosphate after being dropped off on a mountain at a phosphate mine at Boucraa factory of the National Moroccan phosphate company (OCP) situated in the southern provinces, 100 km southwest of the town of Laayoune February 18, 2016. REUTERS/Youssef Boudlal

A vehicle carries untreated phosphate after being dropped off on a mountain at a phosphate mine at Boucraa factory of the National Moroccan phosphate company (OCP) situated in the southern provinces, 100 km southwest of the town of Laayoune, February 18, 2016. REUTERS/Youssef Boudlal

A vehicle carries untreated phosphate after being dropped off on a mountain at a phosphate mine at Boucraa factory of the National Moroccan phosphate company (OCP) situated in the southern provinces, 100 km southwest of the town of Laayoune February 18, 2016. REUTERS/Youssef Boudlal

A phosphate mine at Boucraa factory of the National Moroccan phosphate company (OCP) situated in the southern provinces, 100 km southwest of the town of Laayoune, February 18, 2016. REUTERS/Youssef Boudlal

A vehicle carries untreated phosphate after being dropped off on a mountain at a phosphate mine at Boucraa factory of the National Moroccan phosphate company (OCP) situated in the southern provinces, 100 km southwest of the town of Laayoune February 18, 2016. REUTERS/Youssef Boudlal

A vehicle carries untreated phosphate after being dropped off on a mountain at a phosphate mine at Boucraa factory of the National Moroccan phosphate company (OCP) situated in the southern provinces 100 km southwest of the town of Laayoune February 18, 2016. REUTERS/Youssef Boudlal

Phosphate processing equipment at pumping platform in Laayoune Wharf, February 18, 2016. REUTERS/Youssef Boudlal

A dragline carries untreated phosphate after being dropped off on a mountain at a phosphate mine at Boucraa factory of the National Moroccan phosphate company (OCP) situated in the southern provinces, 100 km southwest of the town of Laayoune, February 18, 2016. REUTERS/Youssef Boudlal

A dragline carries untreated phosphate after being dropped off on a mountain at a phosphate mine at Boucraa factory of the National Moroccan phosphate company (OCP) situated in the southern provinces, 100 km southwest of the town of Laayoune, February 18, 2016. REUTERS/Youssef Boudlal

A bulldozer works at a phosphate mine in Metlaoui, Tunisia April 6, 2012. Phosphate production at Tunisia's Metaloui partially resumed on Sunday and shipments restarted after protesters agreed to temporarily end their sit-in over job demands, the company said. Metaloui, which produces around 60 percent of Tunisia's phosphate output, has been closed by weeks of protests by local youths demanding employment and economic opportunities. Other plants in the south of the country have also been affected. Picture taken on April 6, 2012. REUTERS/Zoubeir Souissi/File

A worker works at a phosphate mine in Metlaoui, Tunisia April 6, 2012. Phosphate production at Tunisia's Metaloui partially resumed on Sunday and shipments restarted after protesters agreed to temporarily end their sit-in over job demands, the company said. Metaloui, which produces around 60 percent of Tunisia's phosphate output, has been closed by weeks of protests by local youths demanding employment and economic opportunities. Other plants in the south of the country have also been affected. Picture taken on April 6, 2012. REUTERS/Zoubeir Souissi/File

A bulldozer works at a phosphate mines in Metlaoui, Tunisia April 6, 2012. Phosphate production at Tunisia's Metaloui partially resumed on Sunday and shipments restarted after protesters agreed to temporarily end their sit-in over job demands, the company said. Metaloui, which produces around 60 percent of Tunisia's phosphate output, has been closed by weeks of protests by local youths demanding employment and economic opportunities. Other plants in the south of the country have also been affected. Picture taken on April 6, 2012. REUTERS/Zoubeir Souissi/File

A bulldozer works at a phosphate mine in Metlaoui, Tunisia April 6, 2012. Phosphate production at Tunisia's Metaloui partially resumed on Sunday and shipments restarted after protesters agreed to temporarily end their sit-in over job demands, the company said. Metaloui, which produces around 60 percent of Tunisia's phosphate output, has been closed by weeks of protests by local youths demanding employment and economic opportunities. Other plants in the south of the country have also been affected. Picture taken on April 6, 2012. REUTERS/Zoubeir Souissi/File

A man rides his motorcycle past a wall covered in graffiti in Metlaoui, Tunisia May 11, 2015. Few shops are open in the Tunisian town of Metlaoui and the local phosphate mine lies idle, blockaded by unemployed young men demanding the government fulfill the economic promises of their country's revolution. The graffiti reads, "We buy and sell University Diplomas". REUTERS/Zoubeir Souissi