Libya's Field Marshal Khalifa Haftar's forces agreed on Saturday to a United Nations-backed truce around the capital Tripoli to mark Eid Al Adha, a spokesman said.
Field Marshal Haftar's forces "announce a halt to all military operations … in the suburbs of Tripoli", Ahmad Al Mesmari said at a press conference in the eastern city of Benghazi.
Mr Haftar's Libyan National Army has been fighting since early April to seize Tripoli from the country's unity government.
At around the same time as Mr Haftar's statement, a car bomb explosion in the eastern city of Benghazi killed two UN staff, several medical sources and the eastern military said.
The UN has been trying to broker a ceasefire in Tripoli, where the LNA launched a surprise attack in April. It has yet to advance beyond the southern suburbs of the capital, which is home to the internationally recognised government.
The explosion happened in front of a shopping mall and bank. At least one burned-out UN car could be seen at the scene.
It was not clear whether fighting over the capital would actually cease after four months of battle that has displaced more than 105,000 people.
Mr Al Mesmari said the truce had gone into effect at 3pm Libyan time on Saturday and would last until the same time on Monday afternoon.
The ceasefire also includes a ban on air strikes, the Tripoli-based government said in an earlier statement, citing humanitarian grounds for the move.
UNSMIL will be responsible for monitoring any violations, the Tripoli government said.
The UN’s Libya envoy, Ghassan Salame, has said a holiday ceasefire should be followed by an international conference to end the war.
In a video conference with the UN Security Council late last month, Mr Salame warned against mounting tensions and called for a ceasefire for Eid Al-Adha.
He also called for the UN Security Council to support the release of 5,000 migrants from Libyan-run detention centres. At least 3,800 men, women and children held without charge are at risk of death from military attacks, he said, advising that his team had drawn up plans to free them.
Over the past four months, 1,093 people have been killed in the fighting and 5,752 wounded, according to the World Health Organisation, while more than 120,000 people have been displaced.
Forces loyal to Tripoli are keeping Field Marshal Haftar's troops at bay on the southern outskirts of the city.
