The city of Benghazi came under attack on Saturday morning, with at least two air raids and shelling of the opposition stronghold's south.
Blasts heard from the centre of the city, as a military plane flew low overheard, AFP reported. The first air strike reported at 7:20 GMT and the second followed around 20 minutes later.
These attacks came after the Libyan government said it was observing a ceasefire.
On Friday evening, residents of Benghazi had braced for an imminent attack, after reports Moammar Kadhafi's forces were just 50 kilometres south of the city.
In Tripoli, Libya's deputy foreign minister had denied there were any plans to attack the city 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.