It was the third straight day that American troops entered the city and U.S. officials said it showed they could move in and out of the capital at will.
In the south, British forces claimed control over Basra, a city of 1.3 million, after a two-week siege. Hundreds of civilians, women in chadors and barefoot children among them, poured into the street to welcome the invaders. Some handed pink carnations to the British troops in appreciation.
The coalition advance on both fronts "reinforces the reality that the regime is not in control of all of the major cities," said Brig. Gen. Vincent Brooks, a spokesman for U.S. Central Command in Qatar.
"The hostilities phase is coming to a conclusion," said Secretary of State Colin Powell, accompanying President Bush to Northern Ireland for a summit with British Prime Minister Tony Blair.
Without elaboration, Powell said the U.S. government is sending a team this week to Iraq to begin laying groundwork for an interim authority.
In other developments:
As dozens of U.S. tanks rumbled through Baghdad with unstoppable force Monday, some Iraqi soldiers jumped into the Tigris River to flee the advancing Americans. Others were captured and placed inside a hastily erected POW pen on the grounds of the blue-and-gold-domed New Presidential Palace.
Tank-killing A-10 Warthogs and pilotless drones provided air cover as Americans briefly surrounded another prominent symbol of Saddam's power, the Information Ministry, as well as the city's best-known hotel, the Al-Rashid. Commanders characterized resistance as mostly disorganized.
An estimated 600 to 1,000 Iraqi troops were killed during the operation, said Col. David Perkins. "We had a lot of suicide attackers today," he said. "These guys are going to die in droves ... They keep trying to ram the tanks with car bombs."
It was the third straight day the Army penetrated Saddam's seat of power. This time, though, there were plans to stay. Rather than withdrawing at nightfall, as units did over the weekend, members of the 2nd Brigade of the 3rd Infantry Division hunkered down for the night.
Several miles away, two soldiers and two journalists were killed in a rocket attack on the 3rd Infantry Division south of Baghdad, the U.S. Central Command reported. Another 15 soldiers were injured in the attack.
Two Polish reporters were abducted by armed Iraqis at a checkpoint in central Iraq, their editors said.
On the other side of Baghdad, Marines encountered tough fighting as they entered the capital for the first time, coming under machine gun fire. Lt. Col. B.P. McCoy said two Marines were killed and two were injured after an artillery shell hit their armored personnel carrier.
At the Pentagon, Gen. Richard Myers, chairman of the Joint Chiefs of staff, said all but "a couple of dozen" of the Iraqi military's tanks had been destroyed in less than three weeks of combat.
Senior officials at the Pentagon said the Army assault into Baghdad was part of an attempt to persuade Iraqi forces that further resistance was futile. The military would like to avoid an all-out urban battle in Baghdad, with its 5 million inhabitants.
Saddam's regime denied it all. "There is no presence of American infidels in the city of Baghdad, at all," insisted Iraqi Information Minister Mohammed Saeed al-Sahhaf.
The Iraqi government maintained control over state-run television and radio — arguably its most important remaining levers of control over the country — and broadcast emotional appeals to resist U.S. forces as well as images of Saddam meeting with key advisers.
While U.S. forces suffered several dead and wounded during the Baghdad battles, Iraqis are having a much worse time, reports CBS News Correspondent Lara Logan from the Iraqi capital.
In addition to wounded Iraqi soldiers being rushed to hospitals, the number of injured civilians threatened to overwhelm medical staff. One hospital reported receiving 175 wounded by midday Monday.
In Washington, Defense Secretary Donald H. Rumsfeld was asked when U.S. forces could declare victory, and whether it would depend on capturing or killing Saddam.
"I don't think it would necessarily hinge on Saddam," he replied.
Rumsfeld suggested that complete victory would likely come "later rather than sooner, simply because it's a big country."