U.S. military officers say the decline in attacks, after months of growing intensity, is the first proof that Saddam's capture and recent U.S. offensives have dampened, but not eliminated, resistance to the occupation.

The average number of daily attacks fell to 18 in the four weeks since Dec. 14, when the coalition announced that Saddam had been captured the day before. In the four weeks before Saddam was found, attacks averaged 23 a day.

During the same periods, U.S. combat injuries dropped only slightly, from 233 in the four weeks before Saddam's capture to 224 in the four weeks after. And the attacks remain deadly: 22 troops killed from Nov. 16 through Dec. 13 and 31 in the comparable period Dec. 14- Jan. 10. But the figures for deaths do not include the 17 U.S. soldiers who died Nov. 15 when two helicopters crashed in the city of Mosul.

U.S. military officers say they are optimistic they are close to breaking the resistance. "We are winning this fight," said Brig. Gen. Mark Hertling, assistant commander of the 1st Armored Division, responsible for security in most of Baghdad.

But Hertling and other military officials also warn that the insurgency is not over. A preliminary investigation indicated that a U.S. Black Hawk helicopter that crashed Thursday near Fallujah, about 30 miles from Baghdad, was hit by ground fire. All nine U.S. soldiers on board died.

Insurgents have harried the U.S.-led coalition and its Iraqi allies since President Bush declared major combat over on May 1. A review of coalition records that list daily assaults from Oct. 30 to Jan. 10 shows guerrilla activity peaked in November at an average of 29 attacks per day. The single worst day: Nov. 11 with 50.

Attacks began falling off when U.S. forces launched offensives based on improved intelligence in December. The decline accelerated with Saddam's capture. The reports are compiled from U.S. and coalition military units across Iraq.

Among the factors U.S. and Iraqi officials say helped cut the number of attacks:

• Saddam's capture ended hopes that he might reclaim power. Though Saddam was not believed to be coordinating the attacks, the inability to capture him caused some Iraqis to believe he might return.

• Offensives that started before Saddam was caught led to the death or capture of leaders and disrupted guerrilla financing and weapons supplies.

But Iraqi and U.S. officials expect violence to continue. "Terror will not end," said Ahmed Kadhum Ibrahim, a senior Interior Ministry official.