Allied warplanes opened the fourth week of the Persian Gulf War yesterday by hammering targets in and around Iraqi cities, while senior military officials said aerial attacks against Iraqi forces in Kuwait will intensify dramatically to prepare for what one commander called an "inevitable" ground war.

Bombers struck Baghdad for the 22nd consecutive night in a relentless campaign that officials said is intended to pressure the Iraqi leadership, cut supply lines and destroy the country's war industry. This strategic objective, the officials added, will be overshadowed increasingly by a tactical campaign against troops, tanks and artillery in a drive to severely weaken the huge Iraqi army entrenched in Kuwait.

Allied officials justified the intensity and breadth of the Operation Desert Storm air attacks as necessary to strip Iraq of both its current war-fighting resources and future war-making capacity. But Iraqi officials said bombs have landed on non-military sites in residential neighborhoods; yesterday, Baghdad authorities claimed that dozens of additional civilians were killed or wounded by the overnight bombing of the Iraqi capital.

"War is a dirty business, and unfortunately there will be collateral damage," U.S. Marine Brig. Gen. Richard Neal told reporters in Riyadh, Saudi Arabia, yesterday. "There's no way we can prohibit it. . . . We have tried our best to limit that collateral damage."

Noting that Iraq has moved increasing numbers of anti-aircraft batteries to civilian building rooftops in Baghdad and Kuwait City, a Pentagon official said those sites now are considered "legitimate military targets," although no decision has been made on whether to attack them. More than 80 percent of the bombing raids on the Iraqi capital have been flown at night by F-117A "stealth" fighters, which remain virtually invisible to Iraqi gunners, the official added, but not infallible in their targeting.

As the allies flew another 2,600 air sorties yesterday, the timing of a prospective allied ground attack continued to generate speculation and controversy. French President Francois Mitterrand declared in Paris that ground fighting is "inevitable" and "will take place this month." Lt. Gen. Peter de la Billiere, commander of British forces in the Persian Gulf, agreed that a land war is "inevitable."

But Neal said U.S. commanders disagree over whether a ground attack will be necessary to evict Iraqi forces from Kuwait. Hours before leaving on a trip to the gulf, Defense Secretary Richard B. Cheney told a House committee that the United States is "not eager to do something foolish {and} put ourselves into a position where we take unnecessary casualties."

But speaking later to reporters aboard his plane, Cheney suggested that bombing alone would reach a point of diminishing returns. "I think that those who are arguing for an air campaign that goes on a few months are to some extent posing a false choice," he said. "There will be a point out there when we'll want to kick in the next stages of the campaign."

The secretary said he and Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, will discuss the war's progress with commanders in Saudi Arabia "to see what steps should come next and report back to the president," who will make any decision on ground combat.

A senior official traveling with Cheney said the secretary's remarks on the plane did not conflict with what he told Congress earlier. "The Hill people wanted to know if it {ground combat} was going to start tomorrow, and when Cheney said no, they said, 'Thank God,' " he said. "Today's discussion was more in the direction of, 'Is it going to happen?' "Air Campaign to Continue

Cheney said a ground attack might draw enemy forces out of their entrenched positions. "You add the {Marine} amphibious element or ground forces in the fashion that forces him {Saddam} to move out of his prepared positions, and it's moving out of those positions that makes him vulnerable once again to the Air Force," he said.

Powell agreed but said he would discuss with top U.S. commanders in the gulf whether a ground attack is the best way to force the Iraqis to move. He emphasized that ground combat would not mean the end of aerial bombardment.

"The air campaign will never end," he said. "It began on the 17th of January and will continue until the whole campaign is over."

Many U.S. civilian and military officials believe that at least several more weeks of tactical bombing will severely diminish Iraq's capacity to resist an allied armored assault -- particularly because Baghdad is unable to replenish its military arsenal. Allied intelligence officers have developed a new and effective technique for detecting Iraqi tank positions, a tactic put to especially good use this week by F-111 bombers dropping laser-guided bombs, a Pentagon official said yesterday.

"They said they killed so many tanks, I can't believe it," he added. Another senior Pentagon official estimated that 10 to 12 percent of Iraq's tank corps in Kuwait has been destroyed.Iraqi Artillery Targeted

Bombers and attack fighters also have begun unleashing their precision missiles and "smart" bombs at Iraqi artillery -- considered the most lethal threat to allied ground troops, according to high-ranking officials and pilots regularly flying missions over the battlefield.

The strategic strikes at Baghdad and other cities are "a way of letting the {Iraqi} leadership know that we care about them and want to bring the war home to them," another Pentagon official said. Allied planners continue to believe that the unceasing bombardment could trigger a coup against Iraqi President Saddam Hussein, he added.

Gen. H. Norman Schwarzkopf, the commander of Operation Desert Storm, appeared to endorse that view in a CBS television interview earlier this week when he suggested that "the entourage around" Saddam may "crack when they see the devastation that's being wrought on the country and on the armed forces."

Several officials also said that continuation of the strategic air campaign against Iraq's defense factories and other military-industrial targets would disable the country's war machine for many years.

Yesterday, the allies' attacks included more than 600 bombing missions against Iraqi targets in southern Kuwait and hundreds more against Republican Guard units, Neal said. A Navy F/A-18 returning from an attack was lost in the Persian Gulf -- apparently to mechanical failure -- and the pilot is missing. An Army UH-1H helicopter crashed, also due to mechanical reasons, killing one soldier and injuring four.

The battleship USS Wisconsin, which has fired numerous Tomahawk cruise missiles since Jan. 17, unleashed its big guns for the first time, firing 11 rounds at an artillery battery, Neal said. Navy A-6 bombers attacked two Iraqi patrol boats, reportedly destroying both.

For the first time in four nights, Iraq launched a Scud missile toward Saudi Arabia at 2 a.m. this morning (6 p.m. Thursday EST). A U.S. Patriot missile destroyed the incoming Scud above Riyadh with a bright flash and thundering boom, showering a deserted parking lot with debris but causing no injuries.

Ground action remained virtually nonexistent except for two brief mortar attacks and an artillery salvo by the allies, officials said. More Planes Flee to Iran

U.S. intelligence analysts have confirmed that another 13 Iranian aircraft fled to Iran Tuesday and Wednesday, Neal said, bringing to 134 the number of planes seeking refuge there, including 109 fighters. Two U.S. F-15 pilots spotted three other Iraqi SU-22 bombers heading for the border, destroying at least two of them and probably the third, Neal added.

The official Iranian news agency IRNA reported that five Iraqi aircraft entering Iranian airspace Wednesday and yesterday either crashed or sustained heavy damage while trying to make emergency landings. One pilot, for example, was killed when his plane "disintegrated" during a landing on a road in Kordestan Province, the report said.

Three Iraqi helicopters also have been shot down this week, including one destroyed by an A-10 Warthog pilot.

In Baghdad, Iraqi officials took correspondents through several neighborhoods allegedly struck during a 12-hour bombardment that ended shortly after 8 a.m. (midnight EST) Wednesday. The officials said allied bombs had destroyed or badly damaged at least 10 houses, killing nearly two dozen civilians and wounding dozens more.

Raja Hamie, a resident of the Adhamiyah district, told an Associated Press reporter from her hospital bed that her husband and three of her children had been killed "when the ground was shaken beneath us and suddenly we were engulfed in a fire." The intended target may have been a still-intact bridge over the Tigris River, about 200 yards from where the neighborhood houses were hit, the AP reported.

Former U.S. attorney general Ramsey Clark, who visited the southern city of Basra earlier this week, told reporters in Baghdad that the bombardment had destroyed houses, hospitals, coffee shops, clinics and law offices in what he called "a human and civilian tragedy."

Baghdad radio warned that Iraq "is waiting impatiently for its decisive battle against all infidel forces. . . . The number of Americans killed will exceed tens of thousands if a ground battle occurs with Iraqi forces . . . which are trained in defensive combat to an extent that no other force in the world has reached." 'Massive Attacks' Planned

To avoid such a fate, allied target planners have been focusing increasingly on battlefield positions in Kuwait and along the Iraq-Kuwait border. "There are going to be massive attacks on {the Iraqis} in the weeks ahead," said de la Billiere, who spoke for many allied ground troops when he noted that "every tank removed {by bombing} is one less tank to go after our troops . . . and every rifle is one less to kill our own men."

Although the British commander said there is "no indication the Iraqi army is going to crack in the immediate future," the enemy will find that the bombardment to date has been "minor {in intensity} compared to what they've got coming." French Defense Minister Pierre Joxe, only in office for a week, said yesterday that the allied bombing already has "certainly caused thousands of deaths."

With respect to a ground offensive, de la Billiere added, "It's going to be the commander's judgment" about the weakness of Iraqi forces rather than strictly objective criteria that will determine when the offensive is launched. Similarly, U.S. generals have said the decision will involve "more art than science" and rely in part on "gut feeling."

In Washington, Saddam's actions continue to cause puzzlement. Senior officials said they cannot detect a pattern that suggests either a desire to become a martyr in the Arab world or an eventual willingness to abandon Kuwait while still claiming victory.

Saddam has not wavered in his statements that Kuwait represents the 19th province of Iraq, a senior administration official said yesterday. That could be read as a sign that the Iraqi leader is prepared to "go down in flames" defending his prize, the official added, although the Iraqi decision to torch oil facilities suggested that Saddam has no plan to stay there indefinitely. 'No Consistent Pattern'

"There is no consistent pattern," the official said. "To me it defies analysis."

The Iraqi leader is "very resourceful, innovative, but extremely unpredictable and probably nonlogical" in his thinking, the official said, and this has forced planners to spend "quite a bit of time looking at what-ifs" as they adapt and adjust their military campaign.

U.S. officials are determined to deny Saddam the ability to emerge from the war as a hero, even if he remains in power.

"I think if his military is clearly defeated in the field, it makes it much harder to claim victory than if something happens and he can withdraw and say, 'I've proven my point, I've stood up to the United States,' " the official said.

Staff writers Dan Balz, Dan Morgan and George C. Wilson in Washington, Molly Moore and Guy Gugliotta in Saudi Arabia and staff researcher Lucy Shackelford contributed to this report.