CAIRO — Heavy clashes between Libyan soldiers loyal to a renegade general and Islamist-led militias killed 38 people, health officials said Sunday, as fighting between rival militias around the capital’s international airport raged on and European nations warned their citizens to leave.

Forces loyal to Gen. Khalifa Hifter battled militias in the eastern city of Benghazi in clashes that started Saturday and continued through early Sunday morning, a security official said. Commando forces regained control of four military camps captured by Islamist militias in the past few days, the official said. The fighting killed eight militia fighters, including the brother of an alleged leader of an al-Qaida-inspired group, the official and a militia website statement said.

The statement published on the website of the powerful Islamist militia Rafallah Sahati confirmed the death of Ahmed al-Zahawi, brother of Mohammed al-Zahawi, the leader of Ansar al-Shariah. U.S. officials believe Ansar al-Shariah was behind the Sept. 11, 2012, attack in Benghazi that killed U.S. Ambassador Chris Stevens and three other Americans.

Rockets fired during this weekend’s fighting hit civilian homes, causing casualties and wounding dozens of people, health officials said.

All officials spoke on condition of anonymity because they were not authorized to brief reporters.

More than two months ago, when Hifter started his offensive to crush Islamist militias and their political backers, Mohammed al-Zahawi vowed to continue fighting, calling Hifter an “American agent.” Hifter once served as dictator Moammar Gadhafi’s top military official but later defected and spent years in the U.S., though American officials say they have not been in recent contact with him.

The fighting in Benghazi came as fierce clashes resumed between rival Libyan militias for control of Tripoli’s international airport. The battle began two weeks ago when Islamist-led militias – mostly from the western city of Misrata – launched a surprise assault on the airport, under control of rival militias from the western mountain town of Zintan.

The fighting has killed dozens and forced residents to flee. Associated Press video of clashes Saturday showed a jet airplane burning and heavy smoke rising over it, as militiamen fired rockets and heavy machine guns.

Shells struck the airport Sunday, while a market and shopping center nearby caught fire.

A statement Sunday by the Libyan Health Ministry said that the ongoing battle for the airport has so far killed 79 people and wounded more than 400. On Saturday, 23 people, including Egyptian nationals, were killed when a rocket struck their house in Tripoli, the Egyptian Foreign Ministry said.

More than three years after Gadhafi’s downfall, Libya is witnessing one of the worst bouts of violence amid growing lawlessness in the country. On Saturday, the U.S. evacuated its diplomats in Tripoli to neighboring Tunisia and shut its embassy. The U.N. Support Mission in Libya and the International Committee of the Red Cross have withdrawn their staff as well.