The site of a former mass grave is seen in Pilice near Zvornik, June 24, 2015. On July 11, 1995, towards the end of the Bosnian War, Bosnian Serb forces swept into a U.N.-designated "safe haven", from where they took 8,000 Muslim men and boys to be executed in the days that followed, dumping their bodies into pits in the surrounding forests. To mark the 20th anniversary of the massacre, Reuters photographer Dado Ruvic identified historic images of the mass graves from the Reuters archive and returned to the locations to photograph the sites today. REUTERS/Dado Ruvic 

The site of a former mass grave is seen in Kamenica near Zvornik, June 24, 2015. On July 11, 1995, towards the end of the Bosnian War, Bosnian Serb forces swept into a U.N.-designated "safe haven", from where they took 8,000 Muslim men and boys to be executed in the days that followed, dumping their bodies into pits in the surrounding forests. To mark the 20th anniversary of the massacre, Reuters photographer Dado Ruvic identified historic images of the mass graves from the Reuters archive and returned to the locations to photograph the sites today. REUTERS/Dado Ruvic 

The site of a former mass grave is seen in Crni Vrh near Zvornik, June 24, 2015. On July 11, 1995, towards the end of the Bosnian War, Bosnian Serb forces swept into a U.N.-designated "safe haven", from where they took 8,000 Muslim men and boys to be executed in the days that followed, dumping their bodies into pits in the surrounding forests. To mark the 20th anniversary of the massacre, Reuters photographer Dado Ruvic identified historic images of the mass graves from the Reuters archive and returned to the locations to photograph the sites today. REUTERS/Dado Ruvic 

The site of a former mass grave is seen in Kamenica near Zvornik, June 24, 2015. On July 11, 1995, towards the end of the Bosnian War, Bosnian Serb forces swept into a U.N.-designated "safe haven", from where they took 8,000 Muslim men and boys to be executed in the days that followed, dumping their bodies into pits in the surrounding forests. To mark the 20th anniversary of the massacre, Reuters photographer Dado Ruvic identified historic images of the mass graves from the Reuters archive and returned to the locations to photograph the sites today. REUTERS/Dado Ruvic 

A chair stands at an abandoned battery factory in Potocari, Bosnia and Herzegovina July 1, 2015. Approximately 6,000 people were held captive at the site. The number of people who were killed at the site is unknown, but it thought to number in the dozens, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic

PICTURE 3 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES

An abandoned battery factory is seen in Potocari, Bosnia and Herzegovina July 1, 2015. Approximately 6,000 people were held captive at the site. The number of people who were killed there is unknown, but it thought to number in the dozens, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic TPX IMAGES OF THE DAY

PICTURE 4 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES TPX IMAGES OF THE DAY

Bullet holes riddle the walls of an abandoned cultural centre in Pilica, Bosnia and Herzegovina June 24, 2015. Around 700 people were killed at the site, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic

PICTURE 8 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES 

Bisina cave is seen in Bosnia and Herzegovina June 24, 2015. The bodies of 34 people were thrown into a hole in Bisina cave, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic

PICTURE 1 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES 

A stage is seen inside an abandoned cultural centre in Pilica, Bosnia and Herzegovina June 24, 2015. Bullet holes riddle the walls at the site where around 700 people were killed, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic

PICTURE 7 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES

A soccer field is seen in Konjevic Polje, Bosnia and Herzegovina July 1, 2015. Approximately 17 people were killed at the site, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic TPX IMAGES OF THE DAY

PICTURE 2 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES TPX IMAGES OF THE DAY

A poster of Russian President Vladimir Putin with the words Republika Srpska (Serb Republic) printed on it is seen inside the main residence of an abandoned agricultural cooperative in Kravica, Bosnia and Herzegovina July 1, 2015. Bullet holes riddle the walls at the site where between 1,000 and 1,500 people were killed, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic TPX IMAGES OF THE DAY

PICTURE 10 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES TPX IMAGES OF THE DAY

A hole in a wall is seen at an abandoned battery factory in Potocari, Bosnia and Herzegovina July 1, 2015. Approximately 6,000 people were held captive at the site. The number of people who were killed there is unknown, but it is thought to number in the dozens, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic

PICTURE 5 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES 

Light shines through windows at an abandoned battery factory in Potocari, Bosnia and Herzegovina July 1, 2015. Approximately 6,000 people were held captive at the site. The number of people who were killed there is unknown, but it is thought to number in the dozens according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic

PICTURE 6 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES 

Plants grow beside a wall of Petkovci dam in Bosnia and Herzegovina June 24, 2015. Between 1,000 and 1,500 people were killed at the site, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic

PICTURE 11 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES 

Clouds pass over a landfill site next to the Drina river in Kozluk, Bosnia and Herzegovina June 24, 2015. Over 1,000 people were killed at the site, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic

PICTURE 12 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES

Plants grow outside the main residence of an abandoned agricultural cooperative in Kravica, Bosnia and Herzegovina July 1, 2015. Bullet holes riddle the walls at the site where between 1,000 and 1,500 people were killed, according to the Missing Persons Institute of Bosnia and Herzegovina. On Saturday, Bosnia marks the 20th anniversary of Europe’s worst mass killing since World War Two - the slaughter of some 8,000 Muslim men and boys by Bosnian Serb forces during five July days in 1995. Even now, the forests and farmland around Srebrenica are yielding bones; over 1,000 victims are missing, tossed into pits then dug up months later and scattered in smaller graves by Bosnian Serb forces trying to conceal the crime. REUTERS/Dado Ruvic

PICTURE 9 OF 12 FOR WIDER IMAGE STORY "SREBRENICA - SITES OF EXECUTION"
SEARCH "RUVIC ABANDONED" FOR ALL PICTURES