Benghazi's clashes followed a week of fighting between rival militias for control of Tripoli International Airport in the capital that has prompted the North Africa country to appeal for international help to stop Libya becoming a failed state.
Tripoli was calmer on Monday, but in Benghazi, militants linked to Ansar al-Sharia attacked an army camp and were repelled by troops and forces loyal to renegade retired general Khalifa Haftar, who has been carrying out a self-declared war on fighters, security sources said.
"Ansar al-Sharia tried to take over one special forces camp, but the special forces and Hafter's forces fought back, using helicopters and military aircraft in their attack," one source said, asking not to be identified for security reasons.
Since the 2011 uprising that toppled autocrat Muammar Gaddafi, Libya's fragile government and new army have been unable to assert authority over rival brigades of former rebels fighting for political and economic influence, Reuters reported.