The conflict was initially between the Yugoslav Army units in Bosnia which later transformed into the Army of Republika Srpska (VRS) on the one side, and the Army of the Republic of Bosnia and Herzegovina (ARBiH) which was largely composed of Bosniaks, and the Croat forces in the Croatian Defence Council (HVO) on the other side. Tensions between Croats and Bosniaks increased throughout late 1992, resulting in the Croat–Bosniak War that escalated in early 1993. The Bosnian War was characterised by bitter fighting, indiscriminate shelling of cities and towns, ethnic cleansing and systematic mass rape, mainly perpetrated by Serb, and to a lesser extent, Croat and Bosniak forces. Events such as the Siege of Sarajevo and the Srebrenica massacre later became iconic of the conflict.