What country tried to force the Muslims out of Bosnia through brutal acts of the military?

Part of the Republic of Bosnia and Herzegovina had seceded: the Serbian-dominated part had proclaimed the Republika Srpska. It was its army (often simply called the Bosnian Serb army) under its General Ratko Mladic that killed many Bosnian civilians. The mass murder of unarmed Muslim men in Srebrenica was a very gruesome case in point.