A bow of an stranded ship is seen on land in the port hit by the tsunami in Palu, Central Sulawesi, Indonesia, October 13, 2018. Picture taken October 13, 2018. REUTERS/Jorge Silva 

A house in the beach hit by the tsunami is seen in Palu, Central Sulawesi, Indonesia, October 13, 2018. Picture taken October 13, 2018. REUTERS/Jorge Silva 

A fishing boat is seen on land in the area hit by the tsunami in the coast line in Palu, Central Sulawesi, Indonesia, October 13, 2018. Picture taken October 13, 2018. REUTERS/Jorge Silva 

A motorcycle drives in front of a stranded ship in the port hit by tsunami on the coastline in Palu, Central Sulawesi, Indonesia October 13, 2018. REUTERS/Jorge Silva 

A fishing boat is seen on land in the area hit by the tsunami on the coastline in Palu, Central Sulawesi, Indonesia October 13, 2018. REUTERS/Jorge Silva 

A fishing boat lies on land while a car is seen stranded in the sea in the area hit by the tsunami on the coastline in Palu, Central Sulawesi, Indonesia October 13, 2018. REUTERS/Jorge Silva 

A fishing boat is seen among palm trees in the area hit by the tsunami on the coastline in Palu, Central Sulawesi, Indonesia October 13, 2018. REUTERS/Jorge Silva 

Apung mosque is seen sinking after the tsunami next to the beach in Palu, Central Sulawesi, Indonesia, October 9, 2018. REUTERS/Jorge Silva TPX IMAGES OF THE DAY 

Apung mosque is seen sinking after the tsunami next to the beach in Palu, Central Sulawesi, Indonesia, October 9, 2018. REUTERS/Jorge Silva 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

Toilets, the only part of a house remaining after it was hit by last week's earthquake and tsunami, are seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

Toilets, the only part of a house remaining after it was hit by last week's earthquake and tsunami, are seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

A toilet, the only part of a house remaining after it was hit by last week's earthquake and tsunami, is seen at Mamboro beach neighbourhood in Palu, Indonesia Sulawesi Island, October 9, 2018. REUTERS/Beawiharta 

An aerial view of the destruction caused by an earthquake in the Balaroa neighbourhood in Palu, Central Sulawesi, Indonesia October 4, 2018. REUTERS/Darren Whiteside 

An aerial view of the destruction caused by an earthquake and tsunami near Palu, Central Sulawesi, Indonesia October 4, 2018. REUTERS/Darren Whiteside 

An aerial view of the destruction caused by an earthquake and tsunami near Palu, Central Sulawesi, Indonesia October 4, 2018. REUTERS/Darren Whiteside 

An aerial view of the destruction caused by an earthquake and tsunami near Palu, Central Sulawesi, Indonesia October 4, 2018. REUTERS/Darren Whiteside 

An aerial view of the destruction caused by an earthquake and tsunami near Palu, Central Sulawesi, Indonesia October 4, 2018. REUTERS/Darren Whiteside 

An aerial view of the destruction caused by an earthquake and tsunami near Palu, Central Sulawesi, Indonesia October 4, 2018. REUTERS/Darren Whiteside 

An aerial view of the destruction caused by an earthquake and tsunami in Wani, Donggala, north of Palu, Central Sulawesi, Indonesia October 4, 2018. REUTERS/Darren Whiteside 

A aerial view of the destruction caused by an earthquake and tsunami in Wani, Donggala, north of Palu, Central Sulawesi, Indonesia October 4, 2018. REUTERS/Darren Whiteside 

Local residents are seen in an area damaged by the earthquake and tsunami in Palu, Central Sulawesi, Indonesia, October 4, 2018. REUTERS/Athit Perawongmetha 

Local residents are seen in an area damaged by the earthquake and tsunami in Palu, Central Sulawesi, Indonesia, October 4, 2018. REUTERS/Athit Perawongmetha 

Damaged properties and a ship are seen after the earthquake and tsunami hit an area in Wani, Donggala, Central Sulawesi, Indonesia, October 3, 2018. REUTERS/Athit Perawongmetha 

Debris and a ship are seen after the earthquake and tsunami hit an area in Donggala, Central Sulawesi, Indonesia, October 3, 2018. REUTERS/Athit Perawongmetha 

A resident walks near the beach after it was hit by the tsunami in Palu, in Indonesia's Sulawesi Island, October 2, 2018. REUTERS/Beawiharta 

Damaged vehicles are seen near a tree after tsunami hit Lolik beach near Palu, Sulawesi island, Indonesia October 1, 2018. REUTERS/Beawiharta 

A couple from an Islamic sect An-Nadzir cross the Mawang Lake for Eid al-Adha mass prayer in Gowa regency, Indonesia's South Sulawesi Province, October 14, 2013. Members of the small sect called An-Nadzir colour their hair, live a basic life of farming and fishing, condemn militancy of any kind, and believe in salvation without discrimination and living in peace with others. Pictures taken October 14, 2013. REUTERS/Yusuf Ahmad (INDONESIA - Tags: RELIGION SOCIETY ENVIRONMENT) 

A woman walks to board a taxi boat heading for the village of Kendari in Indonesia's southeast Sulawesi province July 13, 2011. Taxi boats are the main form of transportation for local residents, linking the different villages on different islets in the province. REUTERS/Yusuf Ahmad (INDONESIA - Tags: SOCIETY TRANSPORT) 

People pray for Irwan, a victim of a passenger plane that crashed into the sea off Kaimana district, in Makassar, Indonesia's South Sulawesi province May 9, 2011. According to local media, the Indonesian passenger plane carrying 27 people crashed on Saturday as it was about to land at the local airport in Kaimana. At least 15 people were killed. REUTERS/Yusuf Ahmad (INDONESIA - Tags: DISASTER TRANSPORT OBITUARY RELIGION) 

Relatives of Irwan, a victim of a passenger plane that crashed into the sea off Kaimana district, cry as his coffin arrives in Makassar, Indonesia's South Sulawesi province May 9, 2011. According to local media, the Indonesian passenger plane carrying 27 people crashed on Saturday as it was about to land at the local airport in Kaimana. At least 15 people were killed. REUTERS/Yusuf Ahmad (INDONESIA - Tags: DISASTER TRANSPORT OBITUARY) 

Relatives of Irwan, a victim of a passenger plane that crashed into the sea off Kaimana district, cries as his coffin arrives in Makassar, Indonesia's South Sulawesi province May 9, 2011. According to local media, the Indonesian passenger plane carrying 27 people crashed on Saturday as it was about to land at the local airport in Kaimana. At least 15 people were killed. REUTERS/Yusuf Ahmad (INDONESIA - Tags: DISASTER TRANSPORT OBITUARY) 

A relative of Irwan, a victim of a passenger plane that crashed into the sea off Kaimana district, cries beside his coffin in Makassar, Indonesia's South Sulawesi province May 9, 2011. According to local media, the Indonesian passenger plane carrying 27 people crashed on Saturday as it was about to land at the local airport in Kaimana. At least 15 people were killed. REUTERS/Yusuf Ahmad (INDONESIA - Tags: DISASTER IMAGES OF THE DAY OBITUARY) 

A fisherman walks through the polluted seawater in the village in Kolaka, a district of Indonesia's southeast Sulawesi, April 14, 2011. The sea water has been polluted by waste from increasing numbers of nickel mining companies in the area. As a result of the pollution, fishermen have been unable to cultivate seaweed and gather other marine products for their livelihood, a fisherman said on Thursday. Picture taken April 14, 2011. REUTERS/Yusuf Ahmad (INDONESIA - Tags: ENVIRONMENT SOCIETY) 

A boat transports fishermen through the polluted village in Kolaka, a district of Indonesia's southeast Sulawesi, April 14, 2011. The sea water has been polluted by waste from increasing numbers of nickel mining companies in the area. As a result of the pollution, fishermen have been unable to cultivate seaweed and gather other marine products for their livelihood, a fisherman said on Thursday. Picture taken April 14, 2011. REUTERS/Yusuf Ahmad (INDONESIA - Tags: ENVIRONMENT SOCIETY) 

Houses belonging to fishermen are seen in the polluted village in Kolaka, a district of Indonesia's southeast Sulawesi, April 14, 2011. The sea water has been polluted by waste from increasing numbers of nickel mining companies in the area. As a result of the pollution, fishermen have been unable to cultivate seaweed and gather other marine products for their livelihood, a fisherman said on Thursday. Picture taken April 14, 2011. REUTERS/Yusuf Ahmad (INDONESIA - - Tags: ENVIRONMENT SOCIETY) 

A fisherman prepares his wooden boat in the polluted village in Kolaka, a district of Indonesia's southeast Sulawesi, April 14, 2011. The sea water has been polluted by waste from increasing numbers of nickel mining companies in the area. As a result of the pollution, fishermen have been unable to cultivate seaweed and gather other marine products for their livelihood, a fisherman said on Thursday. Picture taken April 14, 2011. REUTERS/Yusuf Ahmad (INDONESIA - Tags: ENVIRONMENT SOCIETY IMAGES OF THE DAY) 

A woman pushes her raft loaded with drinking water in the village of the Bajo tribe in Konawe district in southeast Sulawesi province April 11, 2011. REUTERS/Yusuf Ahmad (INDONESIA - Tags: SOCIETY) 

A boy learns to swim with his mother in a Bajo tribal village in Konawe district of Southeast Sulawesi province April 11, 2011. REUTERS/Yusuf Ahmad (INDONESIA - Tags: SOCIETY) 

Workers load bags of nickel ore from state miner Aneka Tambang Tbk onto a ship to be exported, in a harbour at Pomala district in Indonesia's southeast Sulawesi province March 30, 2011. The country accounts for roughly 7 percent of the world's total nickel mine output , according to Reuters data. REUTERS/Yusuf Ahmad (INDONESIA - Tags: BUSINESS ENERGY) 

Children take a bath with seawater on their raft at a seaside residential area in Makassar, South Sulawesi province March 22, 2011. The United Nations' (U.N.) World Water Day is held on March 22 every year to increase people's awareness of water's importance in environment, agriculture, health and trade. REUTERS/Yusuf Ahmad (INDONESIA - Tags: ENVIRONMENT SOCIETY) 

A villager illegally cuts down a tree in a forest in the North Kolaka district of Indonesia's South Sulawesi province November 5, 2010. When U.S. President Barack Obama flies over the vast Indonesian archipelago next week, he will see first hand the size of two of the nation's greatest and most threatened resources: its forests and seas. REUTERS/Yusuf Ahmad (INDONESIA - Tags: ENVIRONMENT POLITICS) 

A villager illegally cuts down a tree in a forest in the North Kolaka district of Indonesia's South Sulawesi province November 5, 2010. When U.S. President Barack Obama flies over the vast Indonesian archipelago next week, he will see first hand the size of two of the nation's greatest and most threatened resources: its forests and seas. REUTERS/Yusuf Ahmad (INDONESIA - Tags: ENVIRONMENT POLITICS) 

A villager illegally cuts down a tree in a forest in the North Kolaka district of Indonesia's South Sulawesi province November 5, 2010. When U.S. President Barack Obama flies over the vast Indonesian archipelago next week, he will see first hand the size of two of the nation's greatest and most threatened resources: its forests and seas. REUTERS/Yusuf Ahmad (INDONESIA - Tags: ENVIRONMENT POLITICS)