Seven people have been killed in clashes between protesters and former rebels aligned with the military in Libya's second largest city of Benghazi.

A doctor in Benghazi's main hospital said the gunfight also left 37 people wounded. He gave no further details about the injured.

A security official in Benghazi said clashes erupted after protesters stormed a base belonging to Libya Shield, a grouping of pro-government militias tasked to maintain security.

The protesters were demanding the gunmen lay down their weapons and come under the full authority of Libya's security forces.

Benghazi was also the site of the September 11 attack that killed Ambassador Chris Stevens and three other Americans.