Outside of Sarajevo, the combatants' successes varied greatly in 1992. Serbs had seized Muslim-majority cities along the Drina and Sava rivers and expelled their Muslim population within months. A joint Bosnian–HVO offensive in May, having taken advantage of the confusion following JNA withdrawal, reversed Serb advances into Posavina and central Bosnia. The offensive continued southwards, besieging Doboj, thereby cutting off Serb forces in Bosanska Krajina from Semberija and Serbia. In mid-May, Srebrenica was retaken by Bosnian forces under Naser Orić. Serb forces suffered a costly defeat in eastern Bosnia in May, when according to Serbian accounts Avdo Palić's force was ambushed near Srebrenica, killing 400. From May to August, Goražde was besieged by the VRS, until they were pushed out by the ARBiH. In April 1992, Croatian Defence Council (HVO) entered the town of Orašje and, according to Croatian sources, began a mass campaign of harassment against local Serb civilians, including torture, rape and murder.