Libyan rebels say they will regroup and bring in heavy weapons after forces loyal to Moammar Gadhafi pounded opposition fighters with artillery, rockets and gunfire a day earlier to stop the rebels'' rapid advance toward the capital.

Mohamad Samir is an army colonel fighting with the rebels. He told The Associated Press on Monday that his forces need reinforcements from the east after Sunday''s setback.

Sunday''s fighting appeared to signal the start of a new phase in the conflict, with Gadhafi''s regime unleashing its air power on the rebel force trying to oust the ruler of 41 years. Resorting to heavy use of air attacks signaled the regime''s concern that it needed to check the advance of the rebel force toward Sirte, Gadhafi''s hometown and stronghold.