Mejra Djogaz, 66, poses with photos of her three sons and husband in Srebrenica, Bosnia and Herzegovina, on July 4, 2015. Now alone, all she has to remind her of her family are a few photos. #

On July 12, 1995, some of the estimated 20,000 Muslim women and children refugees from the eastern Bosnian enclave of Srebrenica wait for transportation, in the village of Potocari, 5 kilometers north of Srebrenica. #

A Bosnian Serb tank crew rests after entering the Srebrenica enclave in eastern Bosnia on July 12, 1995. Over 20,000 refugees fled to the nearby U.N. base of Potocari after Srebrenica fell to the Bosnian Serb army. #

An unnamed woman and her mother, refugees from Srebrenica, cry together because they don't know what happened to the rest of their family, at a U.N. base 12 kilometers south of Tuzla, Bosnia and Herzegovina, on July 13, 1995. The woman holds a carton of mineral water in her hand supplied by the U.N. #

A Bosnian Serb soldier fires a heavy machine gun as his comrade holds the cartridge belt during a “mopping-up” operation near the eastern Bosnian town of Srebrenica on July 13, 1995. #

A Bosnian Muslim woman pleads for international help in tracing thousands of men missing from the town of Srebrenica, taken by Bosnian Serb forces the previous July, during a demonstration in Tuzla on February 1, 1996. The sign behind her reads: “Srebrenica. Where are our husbands, brothers and sons?” #

A Finnish forensic expert looks at the remains of one of more than 100 Muslims killed on a hill, deep in Bosnian Serb Territory on July 2, 1996. The victims were removed to a hospital in the Bosnian government city of Tuzla for identification and later reburial. #

International war crimes investigators take measurements on a warehouse in Kravica (Serb-held territory) on April 12, 1996, where Muslims who were trying to escape the Srebrenica and Zepa enclaves were brought for execution by the Bosnian Serbs. #

International War Crimes Tribunal investigators clear away soil and debris from dozens of Srebrenica victims buried in a mass grave near the village of Pilica, 55 kilometers northeast of Tuzla, on September 18, 1996. #

A Finnish forensic expert places a number next to the skull of a Srebrenica victim found in the hills above the village of Kravica, 15 kilometers northwest of Srebrenica, on July 5, 1996. #

Stacks of unidentified corpses line the walls of an underground shelter at a Bosnian morgue in Tuzla on March 28, 1997. The body bags contain victims found in mass graves and in wooded areas after the 1995 Srebrenica massacre. #

Aida Civic, a Bosnian Muslim refugee woman from Srebrenica, screams as she enters a container with remains of around 3,500 killed Bosnian Muslims, most of them from the former U.N. safe zone of Srebrenica, in an identification center of the Missing Persons Institute in Tuzla on December 10, 2002. #

(1 of 2) Forensic experts of the International Commission on Missing Persons (ICMP) search for human remains in a mass grave in the village of Kamenica on November 4, 2008. #

Plants grow outside the main residence of an abandoned agricultural cooperative in Kravica, Bosnia and Herzegovina, on July 1, 2015. Bullet holes riddle the walls at the site where between 1,000 and 1,500 people were killed in 1995, according to the Missing Persons Institute of Bosnia and Herzegovina. #

A soccer field in Konjevic Polje, Bosnia and Herzegovina, on July 1, 2015. Approximately 17 people were killed at the site in 1995, according to the Missing Persons Institute of Bosnia and Herzegovina. #

Hajra Catic poses under pictures of victims of the genocide in Tuzla on June 11, 2015. Catic is among several thousand women who still search for the remains of their closest relatives 20 years after the Srebrenica massacre of 8,000 Muslim men and boys. With the help of Edmin Jakubovic, who was the last person to see her son injured on the ground, Catic has been constantly searching for her son in the woods. Six months ago, she found a skull and a jaw, but the DNA results are still not available. She fears that if she doesn't find his remains, it will be as he had never existed. All that is left of her son is his picture. #

Srebrenica massacre survivor Nedzad Avdic, 37, touches the engraved names of those killed in a massacre and buried at the Memorial Center in the Srebrenica suburb of Potocari on June 27, 2015. He was 17 when he joined a group of men who tried to flee through the woods. His group was hunted down by Serb soldiers and brought to a school for execution. #

Ema Hasanovic, 5, a young Bosnian Muslim girl, pays her respects near to the coffin of her uncle, in the Memorial center in Potocari, on July 9, 2014. Hundreds of people turned out to pay their respects to 175 victims of the Srebrenica massacre. The remains of the men and boys, found in mass graves and identified through DNA analysis, were buried in Srebrenica during the 19th anniversary of the massacre. #

A grave digger wipes his sweat while preparing graves at a memorial center for victims of the Srebrenica massacre in Potocari on July 5, 2015. Tens of thousands of family members, foreign dignitaries and guests are expected to attend a ceremony in Srebrenica on July 11 marking the 20th anniversary of the massacre in which Bosnian Serb forces commanded by Ratko Mladic killed up to 8,000 Muslim men and boys. Nearly 136 identified victims will be buried at a memorial cemetery during the ceremony, their bodies found in some 60 mass graves around the town. #

In this photo taken on July 4, 2015, Hanifa Djogaz, 66, holds a tobacco tin at the doorstep of her house in Srebrenica. Her son Sabahudin gave his mother the tobacco tin. "Keep this for me, so I can put my cigarettes into something when we get there," he told her. She never saw him again. #

In this photo taken on June 25, 2015, Bosnian Ramiz Nukic walks through ferns on a hill above his house, in the village of Kamenica, near Srebrenica, looking for human remains. There’s rarely a day in which Nukic does not find the remains of at least one murdered boy or man, even 20 years after the Europe’s worst massacre since World War II. #

Senior Forensic Anthropologist Dragana Vucetic of the International Commission on Missing Persons (ICMP) walks through the ICMP center near Tuzla, Bosnia and Herzegovina, on June 11, 2015, during a day at work attempting to identify the remains of a victim of the Srebrenica massacre. #

Senior Forensic Anthropologist Dragana Vucetic of the International Commission on Missing Persons works to attempt to identify the remains of a victim of the Srebrenica massacre at the ICMP center near Tuzla on June 11, 2015. #

Participants in the “March of Peace” hike through mountainous countryside near the village of Nezuk, 150 kilometers northeast of Sarajevo, Bosnia and Herzegovina, on July 8, 2015. More than 10,000 people, including survivors of the Srebrenica massacre, started a 110-kilometer march from Nezuk to Srebrenica following the path along which Muslims fled Serb forces at Srebrenica 20 years ago. #

Srebrenica massacre survivor Nedzad Avdic, 37, walks through the graves of those killed in the massacre and buried at the memorial center in the Srebrenica suburb of Potocari, on June 27, 2015. #