U.S. aircraft bombed a house in the restive city of Fallujah on Monday evening in another attack on the network of Islamic militant leader Abu Musab Zarqawi, U.S. officials said. Local reports said from five to 15 persons were killed.

Also Monday, there was ongoing uncertainty about the fate of a U.S. Marine hostage, Cpl. Wassef Ali Hassoun. Al-Jazeera satellite television said it had received an announcement from a militant group that Hassoun, 24, had been taken "to a place of safety" and that he had promised to quit the Marines. Relatives in Lebanon of Lebanese-born Hassoun said the same statement had been faxed to them, the Reuters news agency reported.

Al-Jazeera did not say whether the announcement was accompanied by a videotape. A series of statements broadcast over the Internet in recent days have made conflicting claims about whether Hassoun was killed. He was taken hostage sometime after his June 19 disappearance from his unit in Iraq.

The U.S. military has carried out a series of air attacks since mid-June on what military officials described as safe houses for Zarqawi's fighters. They said they did not believe any of those attacks killed the Jordanian-born extremist. He is described by officials as the number one wanted man in Iraq, and is thought to have orchestrated a series of kidnappings, murders and suicide bombings in Iraq. U.S. authorities have offered a $25 million reward for him.

Iraqi public sentiment appears to have shifted against Zarqawi and other foreign fighters, but such attacks also generate anger against the continued exercise of U.S. military might. U.S. soldiers fought intense battles in Fallujah before retiring from the city without routing the insurgents last month.

The U.S. military confirmed that the attack on Monday night was made with precision-guided weapons. A military statement said the bombing "underscores the resolve to jointly destroy terrorist networks within Iraq." There was no comment about the outcome of the air raid.

In another incident involving U.S. forces near Fallujah, a U.S. helicopter was hit by gunfire while ferrying a patient to a hospital for surgery. The pilot and co-pilot were wounded, but the craft landed safely, according to Reuters. The military declined to name the pilots. An Army spokesman said the craft was attacked with antiaircraft fire, rocket-propelled grenades and light arms.

Meanwhile, Iraqi officials reported that a section of Iraq's oil export pipeline system had been cut. On Saturday, a fire in another section of the pipeline in southern Iraq had reduced Iraq's export of crude oil. There was no claim of responsibility for either breach.

Iraq's pipelines have been a regular target of saboteurs, as well as thieves trying to steal oil. In the past, the government has moved to repair the lines within days.

For the second time in two days, the new Iraqi interim government did not announce details of its plan for emergency laws and amnesty for Iraqis. There was no explanation given for the last-minute cancellation of a news conference in which the laws were to be announced.

Officials expect Ayad Allawi, the interim prime minister, and his cabinet ministers to announce laws that would authorize the death penalty and permit the imposition of curfews and a form of martial law. The Iraqi army would be used to enforce them. The package may include an amnesty for those who have opposed the U.S. occupation in Iraq.

But officials have been backing away from a statement from the prime minister's spokesman that even insurgents who had killed American soldiers might be given amnesty because their cause was "legitimate."

Now, according to reports here, the amnesty may be granted only to those who did not take part in attacks on occupation or Iraqi forces.