- Oil-rich Libya has been riven by chaos since the Nato-backed uprising in 2011 that killed former leader Muammar Gaddafi.
- Haftar's offensive on Tripoli, launched Thursday, has threatened to plunge the country into a full-blown civil war.
- Haftar's force said Saturday that 14 of its personnel had been killed.
Fighting raged south of Libya's capital Sunday despite a UN call for a two-hour ceasefire, as forces of strongman Khalifa Haftar and the internationally recognised government exchanged air strikes.
The unity government said the fighting had killed 21 people, while the United Nations said there had been "no truce" despite calls for a two-hour pause in fighting for civilians and the wounded to flee.
Oil-rich Libya has been riven by chaos since the Nato-backed uprising in 2011 that killed former leader Muammar Gaddafi, as rival administrations and armed groups have battled for power.
Haftar's offensive on Tripoli, launched Thursday, has threatened to plunge the country into a full-blown civil war and once again derail tentative diplomatic efforts to find a political solution to Libya's woes.
After a pause overnight, fierce fighting flared Sunday morning south of Tripoli between Haftar's self-styled Libyan National Army (LNA) and forces backing the internationally recognised Government of National Accord (GNA).
As clashes raged in the rural area of Wadi Raba and the destroyed international airport south of the capital, a spokesman for pro-GNA forces announced a counteroffensive.
VOLCANO OF ANGER
Colonel Mohamed Gnounou told reporters that operation "Volcano of Anger" aimed at "purging all Libyan cities of aggressor and illegitimate forces", in reference to Haftar's fighters.
The LNA said it had carried out its first air raid on a Tripoli suburb, defying international calls for a ceasefire.
The unity government's health ministry said Sunday at least 21 people had been killed and 27 wounded since the fighting began, without specifying whether civilians were among the dead.
Haftar's force said Saturday that 14 of its personnel had been killed, while the Libyan Red Crescent reported the death of one of its doctors.
Emergency services spokesman Oussama Ali said rescuers "have not been able to enter" the battle zones.
The UN's Libya mission UNSMIL said it was "still hoping for a positive response" to its earlier call for a pause, after a two-hour window it had set for a humanitarian truce passed with no apparent let-up in the fighting.
GNA head Fayez al-Sarraj warned Saturday of a "war without a winner" and said reinforcements were pouring into Tripoli to battle Haftar's forces.
Powerful armed groups from the western city of Misrata and fighters from Zintan and Zawiya -- battle-hardened militiamen who took part in the 2011 uprising against Kadhafi -- have joined the battle.