Several loud explosions and anti-aircraft fire are reported in Baghdad while U.S. and British forces advance on the key southern Iraqi city of Basra.
Witnesses say there were no air raid sirens before the blasts in Baghdad, but aircraft were heard overhead. The city is blanketed in thick smoke after witnesses said Iraq set fire to oil-filled trenches surrounding the capital.
Meanwhile, U.S. Commander General Tommy Franks says he has no plans for a major attack on Basra, because there does not appear to be a large concentration of Iraqi forces there. Earlier, British officials said most regular Iraqi troops appear to have left Basra.
Thousands of Iraqi soldiers have surrendered near Basra and General Franks says U.S.-led forces have taken as many as 2,000 prisoners of war since the start of military action.
In a briefing, General Franks says the coalition military campaign will be "unlike any other in history." He says operations in Iraq are underway in the north, west, south and in and around Baghdad.
In another development, a reporter for Britain's Sky News traveling with coalition troops says an Iraqi ambush left four U.S. soldiers dead in central Iraq, Saturday.
Earlier, a U.S. military spokesman says coalition forces have captured the key Euphrates river crossing point of Nassiriya, 320 kilometers southeast of Baghdad. Late Friday, a massive barrage of guided missiles and bombs left smoke and flames pouring from government buildings in Baghdad, including President Saddam Hussein's Old Palace complex on the banks of the Tigris River.
An Iraqi official says three people were killed in the attack. Iraq's information minister, Mohammed Saeed al-Sahaf said 207 people were wounded during the overnight bombing in Baghdad.
The minister disputed reports of massive Iraqi surrenders and coalition gains in southern Iraq.