SARAJEVO - The remains of nearly 100 people, believed to be Bosnian Muslims and Croats executed in one of the most brutal episodes of the 1990s war, were found in a mass grave, an official said Thursday.

“At the site of Koricanske Stijene we have exhumed 137 clusters of bones, including 86 skulls, which means at least 86 persons, maybe some more,” Lejla Cengic of Bosnia’s Missing Persons Institute told AFP. “The remains were at the bottom of a cave, in a natural pit, and were covered by an enormous amount of rocks,” Cengic said.

The mass grave in central Bosnia was discovered nearby the site of the August 1992 execution of more than 200 civilians, Bosnian Muslims and Croats, previously evicted by Bosnian Serb forces from the northwestern region of Prijedor. The massacre was one of the most brutal episode of the 1992-1995 inter-ethnic war in Bosnia that claimed 100,000 lives.

The victims were separated at Koricanske Stijene from a convoy transporting more than 1,200 people expelled from their homes. They were lined up at the top of a pit and shot at. Dozens of them survived.

To date, eleven wartime members of the Bosnian Serb police forces have been sentenced for the crime.

The exhumation at the site begun in early September. The remains will be transported on Friday to a morgue where their identities will be determined by DNA tests, Cengic said.

“In five previous exhumations in this area, conducted between 2003 and 2013, the remains of 117 victims were found and we were searching for 98 more victims,” she said.

In another mass grave, uncovered last week near the eastern town of Vlasenica, remains of 10 victims, probably Bosnian Muslims killed in 1992, were exhumed.

At the end of the war, 31,500 people were reported missing. Since then, the remains of 25,000 victims have been exhumed from hundreds of mass graves, according to the Bosnian institute, leaving 6,500 unaccounted for.