As the allies hammered out the tough terms of Saddam Hussein's surrender Saturday, dozens of Iraqi tanks opened fire on U.S. forces in the worst violation of the cease-fire. The tank unit was promptly destroyed.

The U.N. Security Council passed a tough resolution setting demands for Iraq to achieve a permanent cease-fire. (See story above.) Many of the points - including the release of all POWs and Kuwaiti detainees - are expected to be raised in a battlefield meeting scheduled Sunday between Iraqi and allied military leaders.No U.S. casualties were reported in the clash in southern Iraq, but two American soldiers died elsewhere in land-mine explosions.

"The battlefield is still very active and very alive," a U.S. commander said. He said a permanent cease-fire is urgently needed to end Iraqi resistance and help locate hundreds of thousands of mines in Iraq and Kuwait.

The Bush administration, meanwhile, said America's force of 530,000 soldiers may begin coming home soon.

Defense Secretary Dick Cheney told CNN he hopes to have a withdrawal plan in place within a week or two. He indicated for the first time that the pullout may take less than the seven months it took to deploy the GIs.

White House chief of staff John Sununu told CNN it was possible that the first American combat troops could be home within a week.

In a radio address to the troops, President Bush praised them for helping build "a renewed sense of pride and confidence here at home" and said their victory meant "the first test of the new world order has been passed."

The U.N. resolution, passed 11-1 with three abstentions, retains the economic and arms embargo against Iraq and demands Baghdad pay reparations. It also orders Iraq to free war prisoners and captured civilians, return stolen property, rescind its annexation of Kuwait and identify the location of the mines and bombs in Kuwait.

The United States and its allies were preparing for a meeting Sunday with Iraqi commanders. Allied generals say the release of all POWs will be their top demand when they talk with Iraq military leaders at a secret location near the Kuwait-Iraq border to discuss the cease-fire. The talks, originally scheduled for Saturday, were delayed one day at Iraq's request.

"If we see stonewalling, if we see a lack of coming to the table and understanding the conditions the president has laid out," the allies will consider going on the offensive again, Brig. Gen. Richard Neal, a spokesman for the U.S. Central Command, told a briefing in Riyadh, Saudi Arabia. "We're not going in there with hat in hand by any stretch of the imagination," he said.

Iraq has advised the International Committee of the Red Cross in Geneva that it is ready for an immediate exchange of prisoners, the relief agency said Saturday. But Iraq still refuses to say how many POWs it has or to identify them by name. Such a disclosure is required by the Geneva Convention.

The harrowing plight of the captives was evident Saturday when the networks showed CBS TV correspondent Bob Simon and his three-man crew after Iraqi authorities freed them from nearly six weeks of captivity.

"I thank God that the four of us are alive," Simon said in a statement broadcast by CBS from Baghdad after they were freed.

"I want to express the hope, the fervent hope, and my prayers that people we met along the way - Americans, British, Kuwaitis, primarily - will be following in my footsteps within hours if not days," the tearful Simon said.

A Soviet spokesman in Moscow said the release followed a telegram two days earlier from President Mikhail S. Gorbachev to Saddam via the Soviet Embassy.

Even as Iraq released its first war captives, another report indicated that some allied POWs may have been killed in captivity. A ranking military officer in Saudi Arabia said the allies believe Iraqis tortured and killed two airmen being held captive. Both were thought to be Britons.

There are 13 known allied POWs, including nine Americans. Sixty-six allied soldiers are missing, including 45 Americans. The coalition partners also are seeking the release of thousands of Kuwaitis believed held in Iraq.

Many of those Kuwaitis were rounded up as Iraqi soldiers beat a hasty retreat from Kuwait City before it was liberated.

Now that Kuwait is back in the hands of Kuwaitis, tales of the nation's underground resistance are beginning to emerge.

On Saturday, the fighters told Associated Press reporter Greg Myre that their exploits included shooting down an Iraqi 747 jetliner carrying 126 Iraqi military officers and faxing maps of Iraqi positions to the allies.

Resistance leaders claimed they used a combination of computers, car bombs, satellite telephones and shoulder-held missiles to wreak havoc on the Iraqis during their seven-month occupation.

In addition to the occasional clashes in Kuwait and southern Iraq, the war's aftermath has plunged the southern Iraqi city of Basra into chaos.

U.S. military sources described "a total breakdown of civil control" in Iraq's second-largest city but no clear indication of rebellion against Saddam.

They said aerial surveillance revealed a city clogged by throngs of people, its central square and main streets in "gridlock" and nearby roads lined with hundreds of tanks, trucks and other military vehicles parked haphazardly.

Meanwhile, an Iraqi opposition leader claimed "more than 90 percent of the army and its commanders" had rebelled against Saddam.