A war crimes court in Bosnia-Herzegovina has handed down the harshest sentences yet to four former members of the Bosnian Serb Army, who were convicted of taking part in the 1995 Srebrenica massacre.

The court in Sarajevo on Friday sentenced one of the men to 43 years in prison; two were given 40-year sentences; and the last was given a 19-year sentence for taking part in the killing of some 800 unarmed Muslim men and boys near the town of Srebrenica.

The July 1995 massacre took place in an area the United Nations had designated a “safe area,” in which battles were not to be fought. Over a series of days, some 8,000 males were executed and buried in mass graves.

The judge noted that the men took breaks from the executions to eat lunch and drink beer while surrounded by the bodies of the victims. She said those actions indicated the killers' systematic attitude toward taking the victims' lives.

While the United Nations has labeled the massacre a genocide, the four men sentenced Friday were acquitted of genocide charges because the prosecution could not prove that they intended to commit genocide.

The four ex-soldiers were under the command of then Bosnian Serb army Chief Ratko Mladic. Mladic is currently on trial for genocide at the U.N. war crimes tribunal in The Hague.