Tripoli, May 22 (AFP) NATO warplanes early today carried out raids against the port of Tripoli and the residence of Libyan leader Muammar Gaddafi near the centre of the capital, a Libyan official said.

"There were two raids on the port and Bab Al-Aziziya", the residence of Gaddafi which has already been targeted several times, the official said.

Earlier, around 12:30 am (2230 GMT yesterday) an AFP journalist heard two explosions and a fighter plane flying over the capital at low altitude.

Taken out in a bus by the authorities, international correspondents were unable to gain access to Gaddafi's residence. An official said after talking to guards in front of the immense residence: "They're expecting new raids, we don't have permission to go in."

Earlier NATO warplanes hit eight vessels of Gaddafi's navy, the alliance said as US President Barack Obama answered constitutional questions regarding the length of the Libyan conflict.