Renegade Gen. Khalifa Haftar's air force was responsible for strikes on Islamist-leaning militia in Tripoli on Monday, one of his commanders said, after weeks of fighting for the capital in Libya's worst violence since Moammar Gadhafi was toppled in 2011.

Fighters from Misrata — east of Tripoli — have been battling militia from the western Zintan region for weeks and have thrown the North African state into anarchy. Zintanis and Misratis worked together to topple Gadhafi but have fallen out since.

The fighting hitherto has been limited to ground action with artillery and rockets. None of the militias had been thought to own warplanes, while the central government has only an outdated air force, badly in need of repair.