Associated Press writer

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 – his desperadoes – 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,” 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,” 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.