Fighting has continued to rage in Libya's capital despite the UN calling for a two-hour humanitarian truce for civilians and the wounded to flee.
The UN made the "urgent" appeal for a truce in the southern suburbs of Tripoli to evacuate wounded and civilians as Libyan forces of military leader Khalifa Haftar pushed to take the capital.
At least 21 people have been killed since the start of a four-day-old offensive by Libyan General Khalifa Haftar to take Tripoli, according to the country's UN-backed government.
Another 27 people have been wounded since the assault began on Thursday, the health ministry in Tripoli said, without specifying whether civilians were among the dead.
General Haftar's self-styled Libyan National Army (LNA) reported 14 deaths among its fighters.
Vehicles and militants, reportedly from the Misrata militia, gather to join Tripoli forces, in Tripoli, Libya. Source: EPA
Forces of the Libyan strongman said Sunday they carried out their first air strike on a suburb of Tripoli, where loyalist fighters announced a "counteroffensive" to defend the capital.
The announcement of the air raid was made on the Facebook page of the "media office" of Haftar's self-styled Libyan National Army as fighting raged around 50 kilometres (31 miles) south of Tripoli.
Forces loyal to Haftar have pressed on with their assault since Thursday despite international calls to halt hostilities.
In the capital, the spokesman for forces loyal to the UN-backed Government of National Accord (GNA), Colonel Mohamed Gnounou, said that counteroffensive "Volcano of Anger" was aimed at "purging all Libyan cities of aggressor and illegitimate forces".
Libya has struggled to counter unrest since the 2011 overthrow of dictator Moamer Kadhafi, leaving dozens of militia to fill the void and ally with either the GNA or a rival administration in the east backed by Haftar.
GNA head Fayez al-Sarraj on Saturday accused Haftar of betraying him and warned of a "war without a winner".
Vehicles and militants, reportedly from the Misrata militia, gather to join Tripoli forces, in Tripoli, Libya. Source: EPA
US troop withdrawal
The US military said Sunday it had temporarily pulled some of its forces out of Libya amid an 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.
Forces loyal to Libyan commander Khalifa Haftar were pressing on at the weekend with the offensive on the capital Tripoli, seat of the internationally-recognised Government of National Accord (GNA).
US Africa Command, headquartered in Stuttgart, Germany, said its mission in Libya involves "military support to diplomatic missions, counter-terrorism 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."
UN Secretary-General Antonio Guterres (C-R) and Special Representative of the Secretary-General and Head of UNSMIL Ghassan Salame (C-L). Source: LIBYAN ARMY MEDIA OFFICE
In the renewed fighting, forces backing the GNA have launched air strikes on Haftar's self-styled Libyan National Army (LNA) around 50 kilometres (30 miles) south of Tripoli.
Tripoli residents fearing that large-scale fighting could break out have begun stocking up on food and petrol.
The head of Libya's internationally-recognised government, Fayez al-Sarraj, on Saturday accused his rival Khalifa Haftar of "betraying" him after the military strongman launched an offensive against the capital Tripoli.
"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," Sarraj said in a televised speech.
The UN Security Council on Friday called on Libyan forces under Khalifa Haftar to halt their advance on Tripoli, warning the military move was putting Libya's stability at risk.
UN chief Antonio Guterres on Friday expressed "deep concern" as he left Libya, a day after fighters led by commander Khalifa Haftar launched an offensive against the capital Tripoli.
"I leave Libya with a heavy heart and deeply concerned. I still hope it is possible to avoid a bloody confrontation in and around Tripoli," he wrote on Twitter.
