Anti-Gaddafi rebels atop a truck scan the area after hearing the sound of a military airplane, at a checkpoint in Ras Lanuf March 8, 2011. Libyan government forces attacked rebels with rockets, tanks and warplanes on western and eastern fronts, intensifying their offensive to crush the revolt against Muammar Gaddafi. REUTERS/Asmaa Waguih (LIBYA - Tags: CIVIL UNREST POLITICS CONFLICT)