Forces loyal to Libyan leader Muammar Qaddafi are reported to be stepping up attacks on rebel positions in Libya's Western Mountains.
A rebel spokesman told Reuters that at least 10 Grad rockets had targeted Zintan late on May 2.
Berber towns in the Western Mountains, close to the border with Tunisia, have been pounded by government forces after joining the rebellion that erupted two months ago.
Refugees say towns in the isolated region are on the brink of starvation.
Further east, a rebel spokesman in the besieged coastal city of Misurata said fighting took place on May 2 near the city's airport.