A warplane crashed in flames on the rebel-held Libyan city of Benghazi after apparently being shot down, an AFP reporter witnessed.
The plane, which had been heard flying over the city for several minutes was suddenly spotted with flames coming from the right rear, before it fell on a residential area south of the city.
A pilot could be seen ejecting as the plane spiralled down towards earth.
The aircraft appeared to be a Russian-built MiG-23, of a type that is used by the Libyan air force, according to the London-based International Institute for Strategic Studies.
Aircraft could be heard over the centre of the city, where explosions were heard throughout the night, as well as continuous gunfire and anti-aircraft fire.
The first air stike came at 7:20 GMT (0520 GMT) and the second followed around 20 minutes later, producing a thick column of black smoke that continued to sit in the sky nearly half an hour later.
At 8:17 am local time, a series of several small explosions, possibly from Katyusha rockets, produced at least seven smaller columns of black smoke south of the city.
The air strikes came after the Libyan government said it was observing a ceasefire that it announced shortly after the United Nations voted to authorise use of force against Moamer Kadhafi's troops.
But the rebel forces who have been trying to overthrow the Libyan leader said his troops had continued to bombard cities, violating the ceasefire continuously since its declaration.
On Friday evening, residents of Benghazi had braced for an imminent attack, after reports Kadhafi's troops were just 50 kilometres (30 miles) south of the city and planning an evening assault.
In Tripoli, Libya's deputy foreign minister had denied there were any plans to attack the rebel bastion and said the government forces would not breach the ceasefire.
"The armed forces are now located outside the city of Benghazi and we have no intention of entering Benghazi," Khaled Kaaim told reporters.
Kaaim also called for the immediate deployment of foreign observers, saying otherwise "the accusations and counter-accusations will not stop."
On Friday, the United States accused Kadhafi of violating the truce, and President Barack Obama delivered a blunt ultimatum to the Libyan leader, threatening military action if he ignores non-negotiable UN demands for a ceasefire and a retreat from rebel bastions.
France is due to host later Saturday what it said would be a "decisive" summit with the European Union, Arab League and African Union, as well as UN chief Ban Ki-moon, on taking UN-sanctioned military action in Libya.
France's ambassador to the United Nations, Gerard Araud, said he expected military intervention within hours of the summit.
