BENGHAZI (AFP) - Libyan rebels battled to defend their gains in the face of an offensive by troops loyal to Moamer Gaddafi on Monday, holding on to strategic Bir Ghanam but suffering casualties elsewhere. Rebels fighting at Zliten, 120 kilometres (75 miles) to the east of Tripoli, admitted they were running low on ammunition as they struggled to hold off an assault by loyalist forces. Abdul Wahab Melitan, a rebel spokesman in the port city of Misrata near Zliten, said forces loyal to strongman Gaddafi had launched an assault on their positions on Sunday in the Souk Telat area. Since then, he said, four rebel fighters have been killed and 40 wounded.