A third Bosnian Serb officer was given a 35-year prison sentence for aiding and abetting genocide. Two others were acquitted of genocide charges but convicted of extermination, murder and persecution, while another two officers were found guilty of lesser charges of war crimes.

It was a dramatic conclusion to the largest trial conducted by the tribunal since it was set up in 1993 to prosecute the worst war crimes offenders even while the fighting was still under way among the ethnic groups in the disintegrating Yugoslavia.

The verdict could have an indirect bearing on the trial of former Bosnian Serb leader Radovan Karadzic, which began last year following his capture in Belgrade in 2008.

Vujadin Popovic and Ljubia Beara, convicted of the worst crime in the war crimes statute, were high-ranking security officers with the Bosnian Serb Army that overran Muslim forces and thinly armed UN troops in the Srebrenica enclave. Drago Nikolic, convicted of aiding and abetting genocide, was a brigade security commander.

All three were in the chain of command under Gen. Ratko Mladic, the Bosnian Serb commander who remains a fugitive 15 years after his indictment.

Sentences for the four other army and police officers ranged from four to 19 years.

The slaughter of some 8,000 Muslim men was the worst massacre on European soil since World War II. Tens of thousands of civilians were evicted from their homes, in what the UN court has called a deliberate attempt to wipe out the Muslim community from that area.

The court has convicted only one other person, Gen. Radislav Kristic, of genocide, but his 2001 conviction was overturned on appeal and reduced to aiding and abetting genocide.

The judges ruled that Popovic, the chief of security for the Drina Corps, organized and watched the execution of prisoners at a school in Orahovac. He "knew that the intent was not just to kill those who had fallen into the hands of Bosnian Serb forces, but to kill as many as possible," the judgment said.

Beara coordinated the murder of Muslim prisoners and organized their mass burials, the judgment said.

The relatives of those massacred said the life sentences were crucial for Bosnia's future. "We are satisfied that they have been jailed for life for genocide," Zumra Sehomerovic of the Mothers of Srebrenica, an association of massacre survivors, said.

But victims' relatives complained that the sentences were too mild for the five other defendants in the case. "We cannot be satisfied completely since justice has been only partially served," said Hajra Catic, the head of the Women of Srebrenica association.