Fierce fighting in the besieged Sunni stronghold of Falluja yesterday killed one US soldier and eight insurgents, casting doubt on a deal Americans had hoped would end one of their biggest problems in Iraq.

　　In central Baghdad, two American soldiers were killed when a chemical storehouse exploded during a raid that may have been part of the hunt for the former Iraqi regime's elusive weapons of mass destruction.

　　And two days after three suicide boats exploded in an attempt to bomb the key offshore oil export terminal near Basra, killing three Americans, al-Qaida operative Abu Musab Zarqawi claimed responsibility for the attack.

　　"We give you good tidings ... your brothers with their boats targeted oil tankers in Mina al-Amiq and Mina al-Bakr," said the statement signed by Zarqawi published on Muntada al-Ansar Islamist Website.

　　Al Arabiya TV broadcast a tape it said showed three Italians held captive in Iraq with a message from their captors who threatened to kill them if the Italian people did not protest their country's military presence in Iraq.

　　"We grant you five days after which we will kill them without any hesitation or any other warning," said the unidentified group's statement, showed by Arabiya.

　　The thorniest military dilemmas in Iraq involve anti-American fighters from the country's two main religious groups - minority Sunni Muslims in Falluja and Shiites in the holy city of Najaf.

　　A deal was struck on Sunday with civic leaders in Falluja, 50 kilometers west of Baghdad, aimed at putting joint patrols of US Marines and Iraqi police on the streets today, when an offer to the insurgents to lay down their heavy weapons expires. Local people were deeply skeptical, however.

　　The battle that broke out shortly before noon yesterday, seemed to bear out those fears.

　　Brigadier General Mark Kimmitt told a news conference that the fighting started when insurgents fired at Marines from a mosque that had been raided earlier by the Marines. He said that Marines returned fire, killing eight insurgents and damaging the mosque. One US soldier died and eight were wounded.

　　After Marines replied with heavy machine guns, jets and Cobra attack helicopters flew overhead. Big explosions threw up thick black plumes of smoke. Residents said they saw corpses on the streets and an imam accused the Americans of hitting his mosque.

　　In Najaf, the other main center of confrontation, 200 US troops entered the holy city, despite a plea from Iraq's senior Shiite cleric not to. They said, however, it was not an offensive against Moqtada al-Sadr's encircled anti-American militia but merely to cover the withdrawal of Spanish troops.

　　(Reuters)