Tripoli residents heard jets followed by explosions at dawn but no further details were immediately available.
In recent weeks Libya has seen the worst fighting since the Nato-backed campaign to oust Muammar Gaddafi in 2011.
Renegade general Khalifa Haftar has declared war on Islamist-leaning forces, part of growing anarchy in the oil producer.
His forces claimed responsibility for air raids on Tripoli on Saturday and last Monday, targeting a group called Operation Dawn.
But this group, consisting mainly of fighters from Misrata, claim on Saturday that it had captured Tripoli's main airport from a rival faction from Zintan in western Libya.