On 11 July , NATO aircraft attacked targets in the Srebrenica area of Bosnia and Herzegovina as identified by and under the control of the United Nations . This was in response to Bosnian Serb forces advancing on the UN-declared Safe Area of Srebrenica . Bosnian Serb warlord Ratko Mladić threatened to kill 50 UN peacekeepers who were seized as hostages and also threatened to shell the Muslim population in Srebrenica if NATO air strikes continued . The UN peacekeepers called off the air strikes and agreed to withdraw from Srebrenica as the Bosnian Serbs promised they would take care of the Muslim population for the peacekeepers to spare their own lives . For two weeks , VRS forces under Mladić killed over 8,000 Bosniaks , mainly men and boys , in the Srebrenica massacre , which remains the worst act of genocide in Europe since World War II
Srebrenica massacre
Srebrenica massacre
Operation Deliberate Force