In April 1992, the JNA began offensive operations against the HV and the HVO in areas of western and southern Herzegovina near Kupres and Stolac. The 4th Military District of the JNA, commanded by Strugar, aimed to capture Stolac and most of the eastern bank of the Neretva River south of Mostar. The fighting around Mostar and JNA artillery attacks on the city started on 6 April. The JNA pushed the HV/HVO force from Stolac on 11 April and Čapljina came under JNA fire. A ceasefire was arranged on 7 May but the JNA and the Bosnian Serb forces resumed the attack the next day. The attack succeeded in capturing a large part of Mostar and some territory on the western bank of the Neretva River. On 12 May, the JNA forces based in Bosnia and Herzegovina became part of the VRS, and the JNA 2nd Operational Group was renamed as the 4th VRS Herzegovina Corps. Croatia saw the JNA moves as a prelude to attacks on southern Croatia specifically aimed at the Port of Ploče and possibly Split. To counter the threat, the HV appointed General Janko Bobetko to command the Southern Front, encompassing the Herzegovina and Dubrovnik areas. Bobetko reorganized the HVO command structure and assumed command of the HVO in the region and newly deployed HV units, the 1st Guards and the 4th Guards Brigades.