In Libya, 17 people have been killed in shelling and sniper fire by forces loyal to Moammar Gadhafi in the western city of Misrata while rocket and artillery attacks on the eastern town of Ajdabiya sent rebel fighters and civilians fleeing. In Misrata, at least 47 people were also wounded in the fighting, during which Mr. Gadhafi's forces fired on a makeshift trauma center. The city has been under government siege for the last seven weeks, leading to a growing humanitarian crisis. Hundreds of civilians are believed to have been killed by fighting and shelling there. In Ajdabiya, bombardment by pro-Gadhafi forces prompted scores of vehicles carrying volunteer fighters and civilians to head north through a thick sandstorm toward the rebel stronghold of Benghazi. Some rebels remained at positions in Ajdabiya to defend the city. The retreat came one day after anti-Gadhafi forces advanced to the outskirts of Brega, an oil-refinery town 80 kilometers to the west.