A roadside bomb in the northern Iraqi city of Mosul has left at least three American soldiers dead and two wounded, Iraqi police in Mosul said. The explosion, the latest to target occupation forces, was detonated as a convoy of US vehicles drove past. A traffic policeman and another witness said the Americans were travelling in civilian clothes in two unmarked vehicles, which were both damaged by two simultaneous blasts at a main square in the city centre. Iraqi police sealed off the area following the explosions, said Assad Mohammed Hussein, 55. "Two 101st Airborne Division (Air Assault) soldiers were killed and two were wounded in an improvised explosive device attack," the division said in a statement. The attack occurred at about 7:30am (0430 GMT) in Mosul, which lies 370kms (230 miles) north of Baghdad. Early Saturday, witnesses also reported an oil pipeline ablaze 15kms north of Saddam Hussein's hometown of Tikrit. Sabotage to pipelines and the decayed state of the infrastructure have hampered attempts to rehabilitate the shattered oil industry. **Day of resistance*** Many people stayed off the streets, schools were closed, and traffic remained lighter than usual as rumors circulated of a "day of resistance". It was unclear where the rumours originated but US authorities had asked their citizens to take extra precautions for today's six-month anniversary of President Bush's announcement that major combat had ended. Many Baghdadis blamed the slowdown on leaflets they had heard about but not seen or alleged messages given by Saddam Hussein. "People are very tense, very jumpy, especially since the attacks are killing civilians and military, Iraqis, Americans and foreigners alike. Bomb scares are even reported in schools and mosques," said businessman Omar Ahmad. "Saddam Hussein or others may want to hurt Iraq with bombings and rumours, but today's paralysis proves that the Americans are so far failing to protect and rebuild Iraq." **Overnight attacks*** Overnight, four Iraqi policemen were wounded in two attacks against patrols, AFP reported police as saying. "A pickup transporting a police patrol came under automatic rifle fire around in the Al-Mujmwa area, north of Mosul," according to a policemen who asked not to be named. "Three policemen were wounded and the attackers fled," he said. A second attack occurred at 6:30am (0330 GMT) Saturday in the Beni Yunes area," the officer said, adding that one policeman was seriously wounded. **PHOTO CAPTION*** US soldiers, right, stand next to blast damaged vehicles in Mosul, northern Iraq, Saturday Nov. 1, 2003. (AP Photo/APTN)