SARAJEVO (Reuters) - A Bosnian war crimes prosecutor indicted six Bosnian Serbs on Friday on charges of killing at least 40 Muslims and Roma early in the Bosnian war of the 1990s and attacking about 1,000 people from the Srebrenica area in eastern Bosnia.

More than 20 years after the Bosnian 1992-95 war ended, many suspected war criminals remain at large and victims are still being found in mass graves.

The six men, who were officials at the Bosnian Serb headquarters in the village of Skelani, are accused of killing civilians, including children, and organized attacks on villages, the Sarajevo-based prosecutor’s office said in a statement.

“In those attacks, at least 40 victims were killed and at least 1,000 (Muslim) Bosniak and Roma victims persecuted from the area of Skelani,” the statement said.

Bosnian Serb forces, helped by the Serb-dominated Yugoslav People’s Army (JNA), attacked Bosnian Muslims in eastern Bosnia in April 1992 with the goal of ethnically cleansing the area slated for their exclusive Serb statelet.

Skelani is near Srebrenica, where Bosnian Serb forces, commanded by General Ratko Mladic, killed around 8,000 men and boys in July 1995, in Europe’s worst atrocity since World War Two. The killings have been declared a genocide by the U.N. war crimes tribunal for the former Yugoslavia (ICTY).

Mladic has been on trial since 2012 at the ICTY over the Srebrenica massacre. Closing arguments are due to begin next week. He has pleaded not guilty and faces a life sentence if convicted.