Explosions shook Tripoli on Tuesday in what the Libyan government said were Nato air strikes on military compounds in the capital, a day after rebels drove Muammar Gaddafi's forces out of a western town.

The rare daytime strikes on the centre of the city, which hit the capital over the course of about half an hour before noon, sent columns of grey smoke into the sky. Nato air strikes, ongoing since March, are usually at night.

Some of the bombs appeared to hit in the vicinity of Gaddafi's vast Bab al-Aziziya residential compound.

A Libyan official, speaking over a loudspeaker in a hotel where foreign journalists are based, said the strikes had hit the Popular Guard compound and the Revolutionary Guard compound.

He gave no information about casualties, and said it would not be possible for reporters to visit the sites because they are not open to civilians.

The Libyan capital and vicinity has come under increased attack by Nato bombers in recent days, with strikes hitting the city and its outskirts every few hours.

Libyan TV said late on Monday Nato had bombed the al-Karama neighbourhood and a civilian telecommunications station.

"The crusading colonial aggressor ... hit and destroyed a communications centre west of Tripoli, severing land communications in some areas. The station is civilian," it said.

Nato said it hit a military "command and control target".

"As long as Gaddafi continues to threaten civilians, Nato will maintain the pressure upon his regime and will continue to degrade his ability to attack the population of Libya," said Lieutenant-General Charles Bouchard, Nato Libya commander.

Gaddafi's troops and the rebels have been in stalemate for weeks, with neither able to hold territory on a road between Ajdabiyah, which Gaddafi's forces shelled on Monday, and the Gaddafi-held oil town of Brega further west.

Rebels control the east of Libya, the western city of Misrata and the range of mountains near the border with Tunisia. They have been unable to advance on the capital against Gaddafi's better-equipped forces, despite Nato air strikes.

But in a sign those strikes may be aiding the rebel advance, the rebels seized Yafran, 100 km (60 miles) southwest of Tripoli, on Monday, after British warplanes had destroyed two tanks and two armoured personnel carriers there on June 2.

Nato Apache attack helicopters were in action in the east on Sunday, destroying a rocket launcher system on the coast near the eastern town of Brega, Britain's Defence Ministry said. – Reuters