Libyan leader Muammar Gaddafi's office in his immense Tripoli residence was destroyed in an air strike early Monday, an AFP journalist said.
A Libyan official accompanying journalists at the scene said 45 people were wounded, 15 seriously, in the bombing. He added that he did not know whether there were victims under the rubble.
"It was an attempt to assassinate Colonel Gaddafi," he affirmed.
A meeting room facing Gaddafi's office was badly damaged by the blast.
NATO warplanes had already late Friday targeted the Bab Al-Aziziya district, where the presidential compound is located.
Heavy explosions shook the centre of Tripoli early Monday as warplanes overflew the Libyan capital. The blasts, the strongest to have hit the city so far, shook the hotel in which foreign correspondents here are staying not far from downtown.
The explosions came at 12.10am in several districts of Tripoli, which has been the target since Friday of intense NATO raids.
Libyan state television transmissions were briefly cut off right after the explosions, before resuming a few minutes later.
An international coalition intervened in Libya on March 19 under a UN mandate to end the bloody suppression of a revolt that started in mid-February against the Kadhafi regime, which has been in power for 41 years.
The North Atlantic Treaty Organisation took over command of the military intervention on March 31.