RIYADH, SAUDI ARABIA — RIYADH, Saudi Arabia -- As the deadline passed for Iraq to begin a withdrawal from Kuwait, the U.S. military command said it saw no evidence that Iraqi forces were preparing to leave and accused them of carrying out "a terror campaign" against Kuwaiti civilians.
U.S. forces appeared poised to launch a ground campaign at any time as armored units plowed through barriers to open the way for infantry and tanks to pour into Iraqi-held territory. At the same time, allied aircraft bombed targets in Baghdad, Basra and other sites inside Iraq and carried out a record number of air strikes in and around Kuwait.
The expiration of President Bush's deadline brought tighter secrecy from the Pentagon. Spokesman Pete Williams refused to confirm or deny reports that the president had authorized Gen. H. Norman Schwarzkopf, commander of Operation Desert Storm, launch a full-scale ground offensive at his own discretion.
But Mr. Williams conceded, "We've clearly reached a turning point in this whole operation with the expiration of the new deadline."
He refused to discuss how the new phase of the war would be directed. "I realize we've done that before," he said. "But we're not going to do it now."
Pentagon officials said reports from the United Nations that Iraq was willing to accept at least some of the conditions set by President Bush were never reflected in the actions by Iraqi troops inside Kuwait. Rear Adm. Mike McConnell, the Pentagon's chief of intelligence, said, "We have seen no movement at all."
While officers in Saudi Arabia said they continued to follow well-established battle plans, the pace of operations accelerated throughout the day and appeared to be influenced by allegations that Iraq was carrying out summary executions of Kuwaiti civilians.
Marine Brig. Gen. Richard I. Neal, the U.S. military spokesman in Riyadh, said at a briefing that executions had begun within the last two days and were directed against civilians stopped at random as well as against people who had been interrogated in the past.
"It seems like a campaign, a terror campaign is going on within Kuwait, in Kuwait City in particular," General Neal said. "We're hearing a lot about executions and other atrocities."
Many of the victims were said to be people previously tortured by Iraqi forces. "They're sort of destroying the evidence, for lack of a better term," General Neal said. "This is terrorism at its finest hour."
Pentagon officials said that as many as 100,000 Kuwaitis had been detained in recent weeks but that an additional 2,000 to 10,000 had been stopped arbitrarily in recent days and in some cases tortured, raped or mutilated. "There's enough evidence to give us high confidence this is in fact happening," Admiral McConnell said.
The reports of executions came one day after the military command said Iraq was setting fires to Kuwait's oil wells and destroying shipping terminals and other facilities, evidence that Saddam Hussein was carrying out a threat to keep Kuwait or destroy it.
Fires were reported burning at 200 wellheads, 50 more than the day before, and at high-pressure wells that could require weeks or months to burn themselves out. They spewed black smoke that colored skies a sickly gray as far away as the Emirate of Qatar, more than 300 miles to the south, and produced a thin rain of soot.
Smoke could hamper helicopters and aircraft assigned to support infantry by striking Iraqi tanks and artillery, but General Neal suggested that allied forces could avoid the affected areas and maintained that there would no significant impact on ground operations.
At least some of the smoke came from allied jets dropping napalm to set fire to trenches filled with oil. The military command was counting on being able to burn off the oil to undo Iraq's strategy of using the trenches to trap an invasion force.
The command meanwhile released new estimates of the effects of around-the-clock air strikes against Iraqi units. General Neal said the equipment destroyed included the following:
* 1,685 tanks, 39 percent of the estimated total of 4,200 tanks in and around Kuwait.
* More than 1,485 artillery pieces, 48 percent of the estimated total of 3,200.
* 925 armored personnel carriers, 32 percent of the estimated total of 2,800.
Those figures reflect the Pentagon's admission that some of its earlier counts of destroyed vehicles were too high. After intelligence agencies objected to the original numbers, aides to General Schwarzkopf, the overall allied commander, agreed that some vehicles previously counted as tanks were in fact trucks and revised their earlier numbers.
The damage is not evenly distributed among the Iraqi units in the field. General Neal said some may have lost as much as 90 percent of their equipment while others may have lost only 10 percent. "Obviously, every tank, every artillery piece, every APC [armored personnel carrier] destroyed, we're very pleased with," said.
Iraq's losses in tanks and artillery may be higher than the latest figures because of the Iraqis' presumed inability to carry out repairs or even routine maintenance during more than five weeks of allied bombing, officers said.
"I would characterize it as an army that has had some severe losses," said Lt. Gen. Thomas Kelly, the Pentagon's chief of operations. "There are units in the theater of operations that have the capability to resist. I do not think they have the capability to prevail."
According to officers in Saudi Arabia, commanders recently changed the targeting strategy for allied pilots by switching the emphasis from bombing tanks to bombing artillery pieces, to reduce the number of guns available to fire chemical artillery rounds.
Pentagon officials warned that Iraqi field commanders using chemical weapons would be held personally responsible and pledged that a U.S. response would be "rapid" and "violent."
"They need to reflect in some depth on the wisdom of using chemical weapons against us, because we will not take that lightly," General Kelly said.
Military action yesterday seemed directed toward clearing paths for an allied invasion force. U.S. and British ships and helicopters swept for mines in waters of the Persian Gulf likely to be crossed by amphibious landing craft.
At the same time, allied aircraft flew a total of 2,900 missions. Pentagon officials said 1,200 went to Kuwait, the highest total ever for a 24-hour period. An additional 100 missions were targeted against positions of the Republican Guard, Iraq's best-equipped infantry and tank units.
Many of the latest efforts were designed to keep the Iraqis guessing about the allies' plans. For several days, the coalition has relied on air assaults by Marine Harrier jets, naval gunfire and deception to confuse Iraq about whether, when or where an 18,000-man Marine amphibious force would come ashore.
Maj. Gen. Harry Jenkins, the amphibious force commander, told pool reporters that several beachfront areas were being prepared for a landing and that the allies would direct heavy fire ++ at several locations to complicate Iraqi efforts to learn where the actual assault would occur.
Artillery units were practicing similar tactics by firing over a large part of Saudi Arabia's border with Kuwait and Iraq. "I think they will wonder, 'Is this a large force out here that is about to make an attack, or is this sort of a diversion or a feint?' " said Brig. Gen. Nick Halley, an artillery unit commander.
At the Pentagon, General Kelly said a ground campaign would unleash the maximum possible firepower, dwarfing the violence unleashed by the air war. "If the ground attack occurs, there will be no doubt in anybody's mind -- and especially in the mind of the Iraqi soldier -- that it has occurred," he said.
There were signs all along the front of ground forces inching forward, prodding here and there over berms of sand and rock. Troops with binoculars could see Iraqi soldiers well enough to help commanders direct mortar fire.
Troops and armored vehicles drove miles beyond the Saudi border and built at least one refueling stop for helicopters. Signs of these missions showed up in unlikely places. On one truck, a message of bravado was traced in the dust, declaring, "This truck has been in Iraq."