"It is clear that elements of the Republican Guard have suffered a comprehensive defeat with very heavy losses and a number of desertions," the spokesman said, adding that US tanks have entered Baghdad to make it clear to the Iraqi people that the coalition forces are advancing and there is a determination to see the job through.

Earlier reports said US contingent of troops supported by tanks and armored vehicles rolled into downtown Baghdad on Saturday for the first time, and US forces seized the headquarters of the Medina Division of Iraq's Republican Guard.

The spokesman also said that Baghdad was "confounded by the speed of the advance and the maneuverability and flexibility of the coalition."

"There are real signs of pressure building up within the leadership," the spokesman said.

"But we know there is still a job of work to be done, and we will do it," he added.

The Republican Guard, regarded as the section of the Iraqi armed forces most loyal to Iraqi President Saddam Hussein, had been deployed to defend Baghdad against advancing US forces.

In another development, reports quoted British military spokesman Al Lockwood as saying that British forces were urging members of Saddam's Baath Party in Basra on Saturday to surrender to British troops who are surrounding the southern city.

Britain, which firmly supports the United States in the war in Iraq, has had its troops concentrated in southern Iraq since the start of the war on March 20.

(Xinhua News Agency April 6, 2003)