The intensified allied bombardment in and around Kuwait has destroyed nearly one-third of Iraq's tank force and artillery in the region, resulting in a rapid erosion of the Iraqi military's fighting capability, U.S. officials reported yesterday.

Expressing continued satisfaction with the progress of the allied campaign, officials also sought to temper criticism of Wednesday's bomb attack in Baghdad by saying they would redouble efforts to avoid killing or injuring civilians.

Lt. Gen. Thomas Kelly, senior operations officer for the Joint Chiefs of Staff, said that the success of the air war, which is now focused on dug-in Iraqi troops and equipment, had left the Iraqi military in a "precarious" position. The stepped up air attacks have now destroyed 1,300 of 4,280 Iraqi tanks, 800 of 2,870 armored personnel carriers and 1,100 of 3,110 artillery pieces in the Kuwaiti military theater, officials reported.

Those figures represented a near doubling in the number of tanks destroyed since Saturday. "What has changed is we have gotten better," Kelly said. "We're having greater success in striking the armored vehicles."

U.S. officials gave no indication how the progress in the air war would affect the timing of anticipated ground action. The commander of British forces in the gulf, Lt. Gen. Peter de la Billiere, was quoted by The Associated Press as saying the allied coalition had agreed on proposed dates for the opening of a ground offensive, but Kelly insisted no decision has been made.

A senior Bush administration official, speaking to wire service reporters yesterday, predicted that the ground war would be quick and violent when it comes. "There will be basically mobile tank battles, and those usually take place very quickly -- very violent, very quick," the official was quoted as saying. "I think it will move swiftly."

The pounding of Iraqi troops continued with another 2,800 sorties yesterday, but there appeared to be a slackening of overnight attacks on Baghdad. U.S. officials maintained, however, that they were justified in targeting the Baghdad building hit Wednesday, which they said was a hardened, military command center, but which Iraqi officials assert was a civilian air raid shelter.

White House press secretary Marlin Fitzwater said President Bush and his top military advisers were "satisfied we . . . did the right thing for the right reasons. And we will continue to attack command and control centers. There will continue to be casualties. There will continue to be civilian losses on both sides."

Iraqi officials in Baghdad continued to pull bodies out of the rubble of the building that was hit by two U.S. laser-guided bombs. There were varying figures on how many Iraqis had been killed in the attack. According to the director of the government mortuary in Baghdad, 288 bodies had been recovered by yesterday morning. But the Information Ministry said at least 400 had died.

One wire service said reporters at the scene counted more than 40 corpses, many decapitated or missing limbs. Information Minister Latif Nassif Jassim accused Bush of being a "war criminal" and said the attack would strengthen Iraq's resolve in the war.

Television carried gruesome images of the bodies and the wreckage, as Iraqis began to bury the dead in grief and anger. Asked about the impact of the television reports, Kelly said: "There are people there who are suffering deep, deep remorse . . . . I feel terribly, terribly sorry for those people. I feel especially sorry for them since it's at least possible that they were sacrificed and that the people who were sent into that building trusted the person who sent them in, and then they were bombed."

The Baghdad bombing reverberated around the world yesterday. Jordan and Tunisia declared days of mourning for the Iraqi civilians who were killed, while Egypt and Syria -- both members of the allied coalition -- accused Iraqi President Saddam Hussein of being responsible for the tragedy. Spain called for a halt in the bombing of Iraqi cities and urged the International Commission of the Red Cross to investigate Wednesday's attack.

The United Nations Security Council met in closed session to debate the war, with some countries expected to question whether the allied air campaign threatens to exceed the U.N. mandates to drive Iraq out of Kuwait and risks the destruction of Iraq itself.Soviets 'Optimistic'

Diplomatic activity also continued in Moscow. The Soviet leadership has told the United States it is "cautiously optimistic" about the situation in the gulf in the aftermath of a visit to Baghdad by a special envoy. But U.S. officials said they did not believe any substantial progress has been made toward ending the war.

Iranian Foreign Minister Ali Akbar Velayati is scheduled to meet with Soviet President Mikhail Gorbachev today. Iraqi Foreign Minister Tariq Aziz is expected to arrive Sunday.

In Baghdad, Yasser Arafat, chairman of the Palestine Liberation Organization, told reporters that Saddam had told him in a meeting yesterday that Iraq could continue fighting the gulf war even if it lasted six years.

"I told Saddam . . . that the gulf war will last three years. President Hussein laughed and told me Iraq could stand the war for six years," Arafat said.

U.S. officials said they would not undertake an overall reassessment of allied targeting strategy as a result of the Baghdad tragedy, but insisted they would do everything they could to avoid causing civilian casualties in the future. Brig. Gen. Richard I. Neal, deputy operations chief for the U.S. Central Command in Riyadh, said commanders there had considered undertaking such precautions as broadcasting some bombing targets to allow civilians time to flee the area, although he said that was not a new consideration.

"That's one of many options we are exploring, and that we continue to explore," Neal said in response to a question. "Obviously we're not fighting the Iraqi people, and any option that we can pursue that might lessen any civilian casualties or collateral damage, we're going to pursue that very aggressively."

But official statements during the day conveyed an ambiguous message, asserting the legal right to attack any military target, regardless of whether civilians were inside, while insisting allied commanders would continue to keep civilian damage and casualties to a minimum.

"We're looking at every resource that's available to us, every method that we can develop to minimize civilian casualties," Kelly said. "What we can't do is let Iraq stop us from pursuing this war by using civilians as shields." He said such a practice violated the Geneva Conventions that help define the rules of warfare.

A senior U.S. military source, while defending the care taken to prevent civilian casualties in the bombing campaign so far, acknowledged that the grim television images showing charred corpses being carried from the bombed Baghdad building had inspired particular concern yesterday as U.S. target selectors went about their job of deciding which site will next feel the fury of allied weaponry.

"I think that the very actions {of} the Iraqis themselves demonstrate that they know damn well that we're not attacking civilian targets," said Gen. H. Norman Schwarzkopf, commander of Operation Desert Storm, "since right now they've dispersed their airplanes into residential areas, they've moved their headquarters into schools, they've moved their headquarters into hotel buildings, they've put guns and things like that on top of high-rise apartment buildings. Under the Geneva Convention, that gives us a perfect right to go after those things if we want to do them. We haven't done it."

According to some news reports yesterday, among the buildings being used as a military command center is the Al Rashid Hotel in downtown Baghdad, where a number of Western correspondents are staying. A hotel official yesterday denied the building housed any military facility and allowed reporters to tour the hotel basement yesterday.

Western correspondents who were also allowed to tour the bombed structure could find none of the communication equipment that U.S. officials said it contained as a military command and control center. Asked about these media reports, Kelly said the reporters had been "duped" by Iraqi authorities.

Fitzwater brushed aside questions about the Baghdad bombing during his briefing yesterday. "Those were all dealt with yesterday," he said. "The issue is settled."

He said in a later interview that Bush believes he retains strong public support for his war goals and that public opinion analysts, such as Robert Teeter, a Bush political adviser, have told the White House that the support is deep enough that an incident such as Wednesday's bombing -- or even the broader issue of a ground war producing significant American casualties -- would not likely shake public backing for the war. Bush Projects War Costs

Bush, said one senior official, "is not only confident he is doing the right thing, he is being told that the public is likely to support him, at least for a period when he takes the next difficult step and in the face of unfortunate days" such as Wednesday.

Bush next week will send Congress a supplemental appropriations bill to cover the cost of the war during the first three months of the year. The administration estimates that the war's costs will total $56 billion for that period, with $41 billion paid by other countries, leaving U.S. taxpayers to pick up the remaining $15 billion.

Despite the attention given this week to the issue of civilian casualties, the allied campaign continued to focus heavily on Iraqi forces in the Kuwaiti theater. Allied bombers carried out 800 sorties on Kuwait yesterday and 200 more against the elite Republican Guard forces deployed along the border north and west of Kuwait as deep reserves guarding Iraq proper.

Another 190 sorties were launched against suspected mobile Scud launchers. The Iraqis switched tactics yesterday by lobbing two Scuds at Saudi Arabia during daylight hours. The two apparently broke apart in flight and fell in the vicinity of Hafr al-Batin, about 60 miles from the Kuwaiti border. Four civilians were injured, a Saudi military briefer said.

U.S. officials reported the loss of an EF-111A Raven electronic warfare plane, which they said crashed in northern Saudi Arabia while returning from a mission. The two crew members were killed. That brought the total number of allied aircraft lost to 27 since the war began Jan. 17.

Discussing the latest estimates of damage to Iraqi forces, Neal said the figures had been rounded off and therefore were not precise. But he and officials in Washington defended them as the best estimates available. Differing Assessments

Intelligence officers under Schwarzkopf's command in Saudi Arabia conduct the battle damage assessments, using some information not available to intelligence agencies in Washington, according to sources. Schwarzkopf's staff has access to reports from Iraqi prisoners of war and tactical, low-level reconnaissance photography that is not routinely provided to Washington. Agencies in Washington have had to rely mainly on high-level satellite photography.

There have been some internal complaints within the Washington intelligence agencies that the Central Command in Saudi Arabia has failed to solicit a second opinion on its estimates, but senior Pentagon officials said this week that the assessments released to the public have been quite conservative.

The destruction of Iraqi ground equipment, as well as a report by the British that more than half of Iraq's estimated 594 hardened aircraft shelters have now been destroyed, were seen as indications of the steady erosion of Iraq's military strength. Defense Secretary Richard B. Cheney and others have commented that the scope of the Iraqi military strength did not fully register on allied officials until they began their systematic air campaign a month ago to destroy it, a campaign that now totals 70,000 air sorties.

Neal attributed the jump in the number of destroyed vehicles since Saturday in part to better weather, which has permitted allied aircraft to fly more bombing missions. But he added that the destruction of Iraq's forces represented "a continuation of a well-orchestrated campaign plan. We're sticking with our plan, and it's a good plan, and it's proved itself already."

Staff writers Ann Devroy, Barton Gellman and David Hoffman in Washington, Nora Boustany in Amman, David Remnick in Moscow, Caryle Murphy in Saudi Arabia and John M. Goshko in New York contributed to this report. Cody reported from Saudi Arabia.