Planes from the US-led coalition were seen overflying the Iraqi capital and several loud explosions could be heard reverberating in central Baghdad.

The bombing of the southern rim continued around 8:00 am (0400 GMT) after a lull of a few hours.

Otherwise, life in central Baghdad, which came under heavy bombing overnight, had a semblance of normality, with public transport buses and cars on the streets.

Several large explosions were heard in central Baghdad around 2:30 am Friday (2230 GMT Thursday) as warplanes flew over the city.

It was not immediately clear what targets had been struck but fire was seen rising from a building in the city centre.

A number of explosions also rocked the northwest outskirts of the capital about 20 minutes later, an AFP reporter said, after an apparently dramatic increase in US-led bombing raids on Baghdad and its rim Thursday.

And at about 3:15 (2315 GMT Thursday), AFP correspondents heard anti-aircraft fire and at least a dozen explosions on the western outskirts of the capital with artillery pounding on the southern approach to the city.

Violent blasts had been heard earlier southwest of Baghdad, the site of Saddam International Airport, following US reports that coalition forces had captured "probably 80 percent" of the site in heavy fighting.

The airport lies just 20 kilometres (12 miles) from central Baghdad.

More than 1,000 US troops were in and around the airport, which came in for new bombing raids overnight that left buildings in flames, according to US officers at the scene.

The US military said elite Iraqi Republican Guard troops inside the airport had been bombed Thursday night and witnesses said dozens of people were killed or injured by heavy artillery fire.

WAR.WIRE