Clashes between government forces and rebels erupted again in eastern Libya Tuesday, as Western warplanes continued to enforce a no-fly zone over the North African country.

Pan-Arab Al-Jazeera TV said clashes erupted Tuesday between Libyan rebels and forces loyal to Libyan leader Muammar Gaddafi on the northeast city of Ajdabiya.

Rebels reportedly were regrouping near Ajdabiya and hundreds of fighters were seen moving towards the outskirts of the city, carrying weapons such as mortars.

Libyan government forces pulled back 100 km from the main opposition stronghold of Benghazi on Monday after Western forces initiated air attacks on Saturday.

The government forces retreated to Ajdabiya, south of Benghazi, after the airstrikes destroyed much of their armor and seriously degraded the country's air defense systems.

Western warplanes Tuesday continued to take off from various bases in Britain, Italy and other places and swept over Libya to enforce the U.N.-mandated no-fly zone.

Also on Tuesday, the U.S. Africa Command, based in Germany, confirmed that a U.S. F-15E fighter jet crashed Monday afternoon (local time) some 40 km southwest of Benghazi due to a malfunction, but the two pilots ejected and had been recovered safely.

The pilots drifted to different locations after ejecting from the jet and both suffered minor injuries, it said.

The Arab League (AL) held a meeting Tuesday to discuss the Libyan situation. The group supported the enforcement of the no-fly zone.

China Tuesday expressed concern over reports the multinational military strike against Libya had caused civilian casualties.

"The U.N. resolution on no-fly zone over Libya is aimed to protect civilians. We oppose abuse of force causing more civilian casualties and more serious humanitarian disasters," Foreign Ministry spokeswoman Jiang Yu said.