BENGHAZI, Libya (AP) — Libyan militias occupied major oil terminals on Friday after clashes with armed forces based in the east and commanded by army chief Gen. Khalifa Hifter, military officials said, amid fears the facilitates could sustain serious damage if the clashes escalate. At least nine soldiers were killed.

Faisal al-Zwei, the spokesman for the 101 Brigade, based at the so-called oil crescent region, told The Associated Press that some 1,000 militiamen in 200 vehicles clashed with the eastern armed forces over the oil terminals of al-Sidra and Ras Lanuf on Friday, forcing the army units to retreat. He said the militias were joined by fighters loyal to eastern militia commander Ibrahim Jedran, the secessionist fighter who took over and oversaw the terminals until Hifter's forces seized them last year. Mohammed al-Basit, the brigade's commander, confirmed the report.

The militias, known as Benghazi Defense Brigades, are comprised of Islamic militants and former rebels who were recently defeated by Hifter's forces in Benghazi, Libya' second largest city. They were joined by militiamen from the western city of Misrata.

Al-Zwei said that the militias advanced on four fronts, despite airstrikes waged by Hifter's air forces. Hifter's army is allied to the internationally-recognized parliament based in eastern Libya. The internationally-recognized government based in the capital Tripoli— which is opposed to Hifter— condemned the fighting and said it has no role in it, according to a statement released by the so-called Presidency Council — the United Nations-brokered body tasked to form the government and which enjoys presidential powers.

Army spokesman Ahmed al-Mosmari said that the forces' decision to retreat was taken to avoid destruction of the oil facilities.

The commander of the oil guards Mufah al-Megarif said that a total of nine soldiers were killed in the fighting. Al-Mosmari said one of the wounded soldiers was shot to death by the militias.

Libya has descended into chaos since the 2011 civil war, which ended with the killing of longtime dictator Moammar Gadhafi. The country has been split into two competing parliaments and governments, each backed by a set of militias, tribes and political factions.

This is not the first time the oil terminals have changed hands in the past three years, heavily impacting the oil production that was finally increasing as it reached 700,000 barrels a day in February.