U.S. troops dashed inside Baghdad on Saturday, blasting targets nestled in palm trees, to show they can move at will against Iraq’s beleaguered defenders. Allies adapted their air campaign to prepare for a climactic ground assault on the capital.

Saddam Hussein’s black-clad militia &045; his desperadoes &045; suddenly surfaced in downtown Baghdad and Iraqi troops deployed at strategic city points at nightfall, in preparation for a showdown.

But tens of thousands of citizens fled, no longer believing the assurances of their leaders that the American ground campaign was being beaten back.

U.S. officials declared a near chokehold on the capital even while warning that many other parts of Iraq are not yet under allied control.

&uot;They’re pretty much cut off in all directions,&uot; Air Force Capt. Dani Burrows, speaking for Central Command, said of Baghdad’s fighters.

While acknowledging Americans raided a suburb, Iraqi leaders talked bravely of prevailing.

&uot;We were able to chop off their rotten heads,&uot; the Iraqi armed forces said in a televised statement, claiming victories no one could see.

Allied warplanes now are flying over Baghdad nonstop, using munitions that include concrete-filled bombs meant to damage fixed targets with less risk to civilian buildings nearby.

Air strikes against the Republican Guard, Saddam Hussein’s loyalist Fedayeen militia and Arab fighters from outside the country followed a daylight raid into Baghdad’s industrial suburbs by at least three dozen tanks and Bradley fighting vehicles.

The aim of the probing attack was to sap morale of the Iraqi fighters, refute public claims of Iraqi officials that they are winning, and perhaps spark surrender or overthrow of Saddam’s government. Americans lost at least one tank and an assault vehicle in periodic firefights.

U.S. officials said they retooled their air strikes to support a coming ground assault on the capital while hoping Iraqis would give up the fight before bloody urban combat became necessary.

In one close-quarters skirmish, Marines with bayonets battled Arab fighters from abroad in a marsh on Baghdad’s southern outskirts.

Two Marine pilots were killed Saturday when their Super Cobra attack helicopter crashed in central Iraq. And the Pentagon confirmed the first combat death of an American woman in the war &045; Pfc. Lori Ann Piestewa, 23, of Tuba City, Ariz., a single mother of two preschoolers.

Piestewa’s body, and those of eight other American soldiers caught in the same ambush, were found during the rescue of American POW Jessica Lynch in Iraq. The death toll for the allied forces passed 100, three-quarters of them American.

Bullish on Baghdad and their progress overall, U.S. officials cautioned that allies did not have control in much of the country. As well, they had only made an incursion in the capital, not staying to hold ground.

&uot;The fight is far from finished,&uot; Maj. Gen. Gene Renuart told a briefing at Central Command’s Qatar headquarters.

President Bush, spending the weekend at the Camp David retreat in Maryland, looked beyond the battle for Baghdad to focus on postwar rebuilding of Iraq, and prepared to meet with British Prime Minister Tony Blair in Northern Ireland on Monday.

A convoy of armored vehicles from the 3rd Infantry Division rolled into Baghdad, although apparently well away from downtown, firing on trucks and other targets half-hidden by leaves and turning them into fireballs.

During their trip into southwestern Baghdad, U.S. troops ran into nests of intense resistance, drawing rocket-propelled grenades and even anti-aircraft cannon, turned on them at ground level.

And on the airport road, Iraqi troops posed for Iraqi photographers standing atop what they said were U.S. armored personnel carriers destroyed in battle Friday and Saturday.

Renuart said the foray &uot;was a clear statement of the ability of coalition forces to move into Baghdad at the time and place of their choosing.&uot;

Iraqis were fleeing the city by the tens of thousands, some in vehicles bearing improvised white flags made from torn-up towels or T-shirts.

In the evening, Baghdad’s streets were bustling with Iraqi troops, militia, loyalists from Saddam’s Baath party and all manner of armed men. Tanks and field artillery faced approaches most likely to be used by the allies.

Members of the Fedayeen, a militia led by Saddam’s son Odai, appeared downtown for the first time since the war began, wearing their distinctive black uniforms. The United States considers them ill-trained but fanatical.

The morale of some Iraqis was clearly crumbling.

&uot;We’ve lost &045; we are losers,&uot; an Iraqi man told a reporter for National Public Radio.

Lt. Gen. Michael Moseley, in charge of the air war, said from his Saudi command post that the Republican Guard, backbone of the Iraqi armed forces, has been hit so hard it &uot;doesn’t really exist anymore.&uot;

Some 6,500 Iraqi soldiers are in allied custody

In northern Iraq, Kurdish forces backed by U.S. warplanes drove Iraqi forces farther back from Kurdish frontiers. The Kurds moved within 20 miles of Kirkuk, Iraq’s second largest oil center, and a similar distance from the oil city of Khaneqin.

In the south, two allied aircraft struck the Basra residence of Saddam’s cousin, Ali Hassan al-Majid, commander of southern forces. He is known as Chemical Ali by opponents who accuse him of once ordering the use chemical weapons against Kurds.

A U.S. official in Washington, speaking on condition of anonymity, said Ali was believed to be home when his residence was hit but that it was not known whether he was killed.

British forces discovered boxes containing hundreds of human remains in a warehouse between Basra and Az Zubayr. Officials said the remains were not from this war.

They also found a catalogue of photographs of the dead, some indicating that the people had been shot.

Along Highway 6 on the southern outskirts of Baghdad, Marine helicopters picked up a 5-year-old boy whose face had been blown away by shrapnel, taking him and his father to an emergency medical center.

Marines also airlifted six other Iraqis for hospital treatment and found that when one man’s civilian clothes were cut open, he wore a military uniform underneath.

At Baghdad’s airport, captured by U.S. troops Friday, soldiers used explosives to clear abandoned buildings and examined an extensive underground complex below the airfield.

Lt. Col. Lee Fetterman, a battalion commander with the 101st Airborne Division, said several hundred Iraqis were killed at the airport, including some with bombs strapped to them who apparently intended to attempt suicide attacks.

Red Cross workers in Baghdad reported several hundred war wounded and dozens of dead had been brought to four city hospitals since Friday.

“The hospitals are finding it increasingly difficult to cope with the continuous influx of wounded,&uot; Muin Kassis of the International Committee of the Red Cross said in Amman, Jordan.

Southwest of the capital, units of the 3rd Infantry captured the abandoned headquarters of the Republican Guard’s Medina division in the town of Suwayrah.

An Army mechanic in his armored vehicle toppled a mosaic of Saddam outside the headquarters, then took a sledgehammer to it. Another soldier clutched the disembodied arm broken off a statue of the Iraqi president.