A Libyan military spokesman has announced a new ceasefire in the campaign against a military uprising, as a second night of international airstrikes on the country appears imminent.

Spokesman Milad Fokehi said the ceasefire, effective from 9pm local time on Sunday (8am Monday NZ time), had been decided following an African Union call for an immediate cessation of hostilities.

"In line with the statement published by the African Union panel at Nouakchott on Saturday and UN resolutions 1970 and 1973, the high command of the armed forces ordered a ceasefire from Sunday at 9pm," Fokehi said.

Muammar Gaddafi's regime had declared a ceasefire on Friday after UN Security Council resolution 1973 authorised any necessary measures, including a no-fly zone, to stop his forces harming civilians in the fight against the rebels.

But his troops continued an assault on the rebel stronghold of Benghazi, prompting US, British and French forces to intervene with air strikes in line with the resolution.