Bosnian police arrested and charged a dozen Bosnian Serbs on Monday for war crimes against Muslim Bosniaks during the country’s war, in 1992. The suspects are accused of participating in an attack on Muslim Bosniaks who were killed and dumped into a mass grave.

“They are charged with murders, torture, rapes, as well as with looting and destroying the property of Bosniaks in the village of Zecovi as part of a bid to drive the Bosniaks from the village,” the Bosnian prosecutor’s office said in a statement following the arrests.

Last year, officials discovered the bodies of more than 150 victims of the attack in a mass grave in the town of Tomasica, near Prijedor, where the suspects were arrested. The Tomasica grave is thought to be the largest one uncovered since the war, containing an estimated 1,000 bodies.

The Bosnian prosecutor’s office said the 12 arrested on Monday were tracked down as part of an investigation into the murders of 29 women and children who were killed in the attack. Authorities are still searching for their bodies, the prosecutor’s statement said.

An estimated 100,000 people, mostly Muslim Bosniaks, were killed during the Bosnian War from 1992 to 1995 as Bosnian Serb forces led an ethnic cleansing drive in the country. So far, the United Nations war crime tribunal has sentenced 16 Bosnian Serbs for crimes against humanity and abuses committed during the war in the Prijedor area. Ratko Mladic, former commanding general of the Bosnian-Serb forces, is on trial and facing life in prison on charges of genocide