Hundreds of U.S. and allied warplanes surprised Iraqi forces with sucessful bombing raids throughout Iraq and Kuwait, in massive raids that began in the predawn darkness over the desert, Defense Secretary Richard B. Cheney said last night.

"So far there has been no air resistance" from Iraq, he told reporters at a Pentagon briefing. "I think it would be fair to say that we achieved a fairly high degree of tactical surprise."

He said reports from the Persian Gulf that the Iraqis might have fired Scud surface-to-surface missiles at Saudi Arabia appeared to be false.

"We have had reports of missile launches, but none of them have been confirmed," Cheney said.

Cheney said the raids were aimed at military targets throughout Iraq and occupied Kuwait by warplanes from the United States, Britain, Saudi Arabia and Kuwait.

The latter apparently referred to aircraft belonging to remnants of the Kuwaiti air force that escaped after the Iraqi invasion in August.

Cheney and Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, said initial reports from U.S. gulf commander Gen. H. Norman Schwarzkopf indicated the air raids had been successful and could be expected to continue for some time.

"They involved hundreds of sorties {missions}," Powell said.

"It is an enormously complex undertaking . . . . It involves hundreds of U.S. and allied aircraft," Cheney added.

He said the strikes included raids on military targets and Iraqi nuclear and chemical warfare facilities but that he did not know how successful they had been. At that point the pilots had not been debriefed.

"The preliminary reports that we have received have been very, very successful," said Cheney during the brief news conference at which he and Powell repeatedly refused to provide details or specify what types of planes were involved.

"The targets being struck tonight are located throughout Iraq and Kuwait," said Cheney, adding that the missions were aimed at removing the offensive military capability of Iraq's President Saddam Hussein.

Powell stressed that Saddam was not a target of the attacks. He refused to confirm unofficial reports that U.S. and allied aircraft had attacked Scud missile sites along the Jordanian border, preventing them from being used to attack Israel as Iraqi officials had threatened to do.

Cheney declined to speculate when U.S. ground forces might be sent into Kuwait.

Powell and Cheney would not say whether the attacking forces had sustained any casualties. Pentagon spokesman Pete Williams told reporters later that assessments from the night raids were sketchy and that the department preferred to wait for any report on possible casualties.

The secretary said he signed the "execute order" for the raids Tuesday afternoon on orders from President Bush. He said the raids were not carried out until Congress had been notified, requirements of a U.N. resolution had been fulfilled and all efforts at a political settlement had failed.

Cheney said the timing of the attack was based on "among other things, the expiration of the United Nations deadline . . . . I think it was affected in part as a result of consultation with our allies. But it also was based upon the advice of our senior military commanders in terms of picking a time when conditions appeared to be most favorable for undertaking the operation.

"I think it would be fair to say . . . that the initial reaction from the Iraqis is such that I'm generally of the opinion that we achieved a fairly high degree of tactical surprise," Cheney said.