FILE - In this Aug. 14, 2017 file photo, Libyan militia commander General Khalifa Hifter meets with Russian Foreign Minister Sergei Lavrov in Moscow, Russia. The U.N. chief says he's worried about a major armed showdown in Libya and is urging warring factions to instead turn to dialogue. Forces loyal to Hifter, who commands the self-styled Libya National Army that's based in the country's east, took control overnight Wednesday April 3, 2019, of the town of Gharyan, 50 kilometers (31 miles) from Tripoli, without major clashes. (AP Photo/Ivan Sekretarev, File)

BENGHAZI, Libya - Forces loyal to rival Libyan army commander Khalifa Hifter said Saturday they seized control of the main airport in Libya's capital Tripoli, two days after Hifter ordered his forces to seize the seat of Libya's U.N.-backed government.

Hifter's media office said in a post online that they took full control of the Tripoli international airport and were working to secure the facility. They posted photos of troops apparently inside the airport, saying "we are standing at the heart of the Tripoli international airport."

Hifter's offensive on Tripoli could plunge the oil-rich country into another spasm of violence, possibly the worst since the 2011 civil war that toppled and later killed longtime dictator Moammar Gadhafi. The country is governed by rival authorities: The internationally backed government in Tripoli and the government in the east, which Hifter is aligned with. Each is backed by an array of militias.

Fayez Sarraj, chairman of the Presidential Council of Libya, said his government had offered concessions to Hifter "to avoid bloodshed and to end divisions" and was surprised by Hifter's order to take the capital.

"We were stabbed in the back," he said Saturday in televised comments, adding that his forces would confront Hifter's troops with "force and determination."

The Tripoli airport has not been functional since fighting in 2014 destroyed much of the facility.

The media office said that troops also captured the area of Wadi el-Rabeia, south of Tripoli, amid clashed with militias loyal to Sarraj.

Ahmed al-Mesmari, spokesman for the self-styled Libyan National Army led by Hifter, said 14 troops had been killed since Hifter declared the offensive. He said rival militias launched four airstrikes Saturday targeting Hifter's position in the town of al-Aziziya, but that no casualties had been reported.

Al-Mesmari said Hifter's forces declared Tripoli a no-fly zone for warplanes.

Hifter announced Thursday he was deploying his forces toward Tripoli, sparking fears that the tensions could be escalating out of control as militias from the western cities of Zawiya and Misarata said that they have mobilized to confront Hifter.

He also put at risk upcoming peace talks between Libyan rivals brokered by the U.N. aimed at drawing a roadmap for new elections.

The U.N. Security Council on Saturday called on Hifter forces to halt all military movements and urged all forces in Libya "to de-escalate and halt military activity."

The U.N. envoy for Libya, Ghassan Salame, said the UN is determined to hold the planned national conference later this month to set time for possible elections.

Speaking at a news conference in Tripoli, he said he was striving to prevent the new crisis from getting out of control. "We have worked for one year for this national conference, we won't give up this political work quickly," he said.

News from © The Associated Press, 2019