A building on fire that witnesses say was hit by a rocket burns after clashes between rival militias in the Sarraj district of Tripoli. Reuters

(Reuters) -- Unidentified war planes attacked targets in Libya’s capital Tripoli Sunday, residents said, hours after forces from the city of Misrata said they had seized the main airport. Tripoli residents heard jets followed by explosions at dawn, but no more details were immediately available.

In recent weeks, Libya has seen the worst fighting since the NATO-backed campaign to oust Moammar Gadhafi in 2011. Renegade Gen. 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 Saturday and last Monday, targeting a group called Operation Dawn. But this group, consisting mainly of fighters from Misrata, said Saturday that it had captured Tripoli’s main airport from a rival faction from Zintan in western Libya.

In the campaign to overthrow Gadhafi, fighters from Zintan and Misrata were comrades-in-arms. But they later fell out and this year have turned parts of Tripoli into a battlefield.

Libya’s neighbors and Western powers worry Libya will turn into a failed state as the weak government is unable to control armed factions.

Growing Divisions

Libya faces the prospect of two competing parliaments, after the claimed Misrata victory at Tripoli airport, which Reuters could not immediately confirm.

In a challenge to the parliament elected June 25, an Operation Dawn representative called for the old General National Congress, or GNC, to be reinstated. Misrata forces have rejected the new House of Representatives, where liberals and lawmakers campaigning for a federalist system have made a strong showing.

In a sign of deep divisions between Libya’s regions and political factions, the House of Representative declared Operation Dawn as well as militant Islamists such as the Ansar al-Sharia as “terrorist groups.”

The House of Representatives, which has fled to Tobruk in the east with senior officials to escape fighting, asked Haftar to fight the Operation Dawn forces. Haftar launched a campaign against Islamists in the eastern city of Benghazi in May and threw his weight behind the Zintan fighters. His air defense commander, Sager al-Jouroushi, told Reuters Saturday that his forces were responsible for the airstrikes Saturday and a similar attack last Monday.

Misrata forces have blamed the airstrikes on Egypt and the United Arab Emirates, two countries that have cracked down on Islamists. Libya’s government has said it does not know who is behind the attacks.

Egyptian President Abdel-Fattah el-Sissi denied his country had conducted any airstrikes or other military operations in Libya, the MENA state news agency quoted him as saying. Western and NATO officials have also denied any involvement.

Fighting also erupted between Haftar’s troops and allied army special forces with Islamists in two Benghazi suburbs Saturday, killing eight soldiers and wounding 35, medics said.

The violence has prompted the United Nations and foreign embassies in Libya to evacuate their staff and citizens, and foreign airlines have largely stopped flying to Libya.

Libya’s central government lacks a functioning national army and relies on militia for public security. But while these forces receive state salaries and wear uniforms, they report in practice to their own commanders and towns.