Five days after U.S. and allied forces started a massive air war against the Iraqi military, major gaps remain in what is known about the progress of the battle.

This is a result of several factors: a welter of conflicting reports coming back from the front, an obvious desire by government spokesmen to bolster public support for U.S. forces, and a general reluctance to make public anything that might give aid and comfort to the enemy.

Military officials have said U.S. and allied aircraft have conducted thousands of bombing raids on enemy forces, but they have said little about which Iraqi targets were attacked or how the attacks occurred.

Shifting military statements over the past three days have produced continuing uncertainty about the capabilities of the remaining Iraqi forces, including the current strength of the elite Republican Guard; the number of Scud missiles destroyed; the remaining number of Iraqi airplanes; and the ability of Iraqi President Saddam Hussein to communicate with his troops in Kuwait.

No U.S. military official has been willing to describe possible damage to civilian facilities, as well as military targets struck by tens of millions of pounds of U.S. and allied explosives. The bombing has involved at least 12 types of combat aircraft, including dozens of high-flying B-52 bombers equipped with huge, unguided munitions.

But the Pentagon has not allowed interviews with B-52 pilots, shown videotapes of their actions or answered any questions about the operations of an aircraft that is the most deadly and least accurate in the armada of more than 2,000 U.S. and allied aircraft in the Persian Gulf region.

Nor has the military said how many hits were made on economic targets such as Iraqi oil refineries and manufacturing plants, or explained the rationale for striking any targets that could play a key role in Iraq's recovery after the war.

When asked if he would answer some of these questions at the daily Pentagon briefing yesterday, Army Lt. Gen. Thomas Kelly, senior operations officer for the Joint Staff, said, "The short answer is no."

He and Rear Adm. John M. McConnell, chief intelligence officer for the Joint Staff, explained their reluctance by citing uncertainty and official secrecy, issues that have hampered accurate reporting of war news for as long as wars have been fought.

The U.S. military's daily accounts of the war at the Pentagon and the media center in Riyadh have settled into a routine that provides few facts and more and more jousting between officials and reporters.

Kelly and McConnell, or their counterparts with the U.S. Central Command, have provided a daily tally of U.S. military personnel

in the region, the cumulative number of sorties flown by U.S.

and allied planes, the number of Iraqi Scud missiles fired in the

past day, the number of allied or enemy planes shot down, and the number of airmen missing in action.

Until yesterday, U.S. military officials also repeatedly said the estimated "success rate" for bombing missions over Iraq was 80 percent, while declining to say which targets were knocked out.

Judging from initial press accounts, the estimated "success rate" played a major role in fixing a public impression of great progress in the campaign to defeat Saddam.

But this number, as well as the cumulative number of sorties, tends to exaggerate both the magnitude of the conflict and its impact on Iraqi military forces, some U.S. officials now say. Sorties, which Kelly said yesterday totaled 8,100, include thousands of missions flown for combat support, including refueling, transport and air defense -- many within Saudi Arabia.

The "success rate," officials said yesterday, reflects the judgment of returning pilots that they correctly sighted their targets and released their munitions. It does not reflect the U.S. military's assessment of how many targets were successfully destroyed, a number that several sources said is much lower.

"If I took every report and counted a kill on every report I received, the Iraqi air force would have been eliminated a long time ago," McConnell said on Saturday. "My responsibility is to sort that out piece by piece."

One source briefed on the Pentagon's "bomb damage assessment" reports after the first day of fighting said the initial air missions had achieved an average of 50 percent of the desired level of damage. Other officials said the shortfall forced repeated strikes against both "soft" and resilient or heavily defended Iraqi targets.

Pentagon spokesman Pete Williams declined to provide more detailed information, stressing the need for secrecy about combat operations: "If we release . . . preliminary bomb damage assessments saying, 'Well, on this target, X, we didn't achieve quite the success we wanted,' that's more or less a notice to the Iraqis that we'll come calling again."

Kelly also cited uncertainties caused by overcast skies that have inhibited post-attack reconnaissance.

"We would like a little bit more time to be able to measure what the success in that deliverance has been," he said. "We are satisfied with the progress we're making within the parameters we have to measure that progress."

No U.S. military official has disclosed what "parameters" the classified battle plan incorporates to determine success or failure, a circumstance that bars any independent judgment.

However, Williams and other Pentagon officials said yesterday that key early goals of eliminating most fixed and mobile Iraqi Scud missile launchers and winning control of Iraqi airspace have not been achieved, contrary to statements by some officials during the weekend.

Several congressional aides, speaking on condition they not be identified, said that in its briefings, the Bush administration was presenting a picture of the war designed to bolster domestic support, keep together the coalition of disparate nations that oppose Iraq, and push Saddam toward early capitulation.

Less positive information about the war's progress has emerged from closed briefings for legislators conducted by U.S. military and intelligence officials yesterday and last Friday, including low estimates of confirmed kills of Iraqi aircraft and Scud missile launchers, and of damage to the Iraqi Republican Guard.

"Giving you a clear picture of what's happening is giving him {Saddam} a clear picture of what's happening," said Navy Lt. Cmdr. David Knox, deputy of the media branch of the Riyadh Joint Information Bureau.

But Associated Press reporter Richard Pyle, expressing sentiments widely held by reporters in Saudi Arabia, said, "We should have a better idea of the targets that have been struck because the Iraqis certainly know."

Reporters in Saudi Arabia are

not allowed to do independent reporting without a military escort, and are not supposed to interview any service member without a military public affairs officer's permission.

"The whole structure is inherently manipulative. We have no independent access," said an American radio reporter. "Technically, I can be thrown out of this country for talking to an American serviceman and that I find ludicrous."

The Pentagon has allowed interviews with pilots of the super-secret F-117 "stealth" fighters and high-performance F-15 and F-16 fighter-bombers, and has shown selected videotapes of these and other planes planting their bombs at the door or down the air shaft of Iraqi buildings.

But by barring access to pilots of the B-52s while allowing interviews with other pilots and tapes of successful missions, the Pentagon has reinforced the idea of a so-called surgical air campaign, in which military targets are obliterated without causing civilian deaths -- or "collateral damage," in military lingo.

Staff writer Caryle Murphy contributed to this report from Saudi Arabia.