TRIPOLI   -   The army behind Libya’s UN-backed government has announced a counteroffensive to defend Tripoli, vowing to reclaim all areas seized by forces loyal to renegade General Khalifa Haftar, who have been marching on the outskirts of the capital.

Colonel Mohamed Gnounou told reporters in Tripoli on Sunday that the counteroffensive, dubbed “Volcano of Anger”, was aimed at “purging all Libyan cities of aggressor and illegitimate forces”.

The announcement came as Haftar’s forces said they conducted the first air raid on a Tripoli suburb as part of their aim oust the internationally-recognised Government of National Accord (GNA) and control Tripoli. The alleged strike came after GNA forces launched air raids on Haftar’s self-styled Libyan National Army (LNA) around 50km south of Tripoli on Saturday, reportedly killing one person.

Meanwhile, the UN mission in Libya (UNSMIL) made an “urgent appeal” for a two-hour truce in the southern suburbs to evacuate the wounded and civilians caught in the fighting.

“[UNSMIL calls on] all armed parties in the Wadi Rabi area, Al-Kayekh, Gasr Ben Ghachir and Al-Aziziya to respect a humanitarian truce (between 14:00 and 16:00 GMT) to secure the evacuation of wounded and civilians by rescue teams and the Libyan Red Crescent”.

Fearing that large-scale fighting could break out, the city’s resident have begun stocking up on food and fuel. At least 35 people, including civilians, have been killed on both sides since Haftar launched his offensive four days ago.

The health ministry of the Tripoli-based government said in a statement that at least 21 people were killed, including a doctor, and 27 others were wounded. Ahmed al-Mesmari, spokesman for Haftar’s forces, said Saturday that 14 troops were killed.

The internationally recognised GNA controls Tripoli, situated in northwestern Libya, while the LNA is allied to a parallel administration based in the east of the oil-rich country, which splintered into a patchwork of competing power bases following the overthrow of former leader Muammar Gaddafi in 2011. On Sunday, the US military said it had temporarily pulled some of its forces out of Libya amid the upsurge of fighting in the North African country. “Due to increased unrest in Libya, a contingent of US forces supporting US Africa Command temporarily relocated from the country in response to security conditions on the ground,” it said in a statement. It did not detail how many military personnel had been withdrawn from Libya.

US Africa Command, headquartered in Stuttgart, Germany, said its mission in Libya involves “military support to diplomatic missions, counterterrorism activities, enhancing partnerships and improving security across the region”.

It said it would “continue to monitor conditions on the ground in Libya and assess the feasibility for renewed US military presence as appropriate”. “The security realities on the ground in Libya are growing increasingly complex and unpredictable,” said US Marine Corps General Thomas Waldhauser, commander of US Africa Command.

“Even with an adjustment of the force, we will continue to remain agile in support of existing US strategy.” On Saturday, the head of the GNA accused Haftar of “betraying” him after the latter launched his military offensive on Tripoli. In a televised speech, Fayez al-Sarraj said Haftar’s forces would meet firm resistance from forces loyal to the GNA.

“We have extended our hands towards peace but after the aggression that has taken place on the part of forces belonging to Haftar and his declaration of war against our cities and our capital ... he will find nothing but strength and firmness,” al-Sarraj said. He also warned of “a war without winners”.