IRAQ U.S. helicopter crashes; police official assassinated

Militants continued threats against Iraqis who cooperate with allied forces.
BAGHDAD, Iraq (AP) -- A U.S. military helicopter crashed today into a river west of Baghdad, police and witnesses said. There was no immediate word on casualties.
The crash took place in the city of Haditha, 120 miles from the capital.
"We are aware of an incident with a coalition helicopter near al-Haditha," the military command in Baghdad said without providing details.
Meanwhile, gunmen assassinated the deputy police chief in the northern city of Mosul today, and militants warned of further attacks on Iraqi security forces and Kurdish militiamen, accusing them of protecting "infidel" Americans.
Attack on shrine
In Baghdad, attackers fired a rocket-propelled grenade at a major Shiite Muslim shrine overnight, officials at the shrine said. The RPG punched a hole in an outer wall of the Kazimiyah shrine in a northern neighborhood of the capital but caused no injuries.
The attack on the shrine came on the fourth day of the Islamic month of Muharram, a sacred period when thousands of Iraqi Shiites and Iranian pilgrims have converged on Kazimiyah, where two Shiite saints are buried, and other Shiite shrines in cities of southern Iraq.
U.S. officials have said insurgents seek to fan tensions between Iraq's Shiite majority and Sunni minority into a civil war. At the same time, guerrillas have stepped up attacks on Iraqi police and security forces, which are due to take a front-line role against the insurgency once the Americans transfer power to the Iraqis on June 30.
Gunmen in a car opened fire on Mosul's deputy police chief, Brigadier Hikmat Mohammed, as he was headed to his office this morning, killing him, Police Lt. Ziad Mahmoud said.
Hours earlier, a previously unknown militant group, the Mujahedeen Brigades in Iraq, distributed leaflets at police stations in the northern city of Kirkuk, threatening attacks on police and Kurdish militias for cooperating with Americans.
Police Col. Adel Ibrahim said he thought the group may have been behind the attack Monday in which a suicide bomber detonated his explosive-laden car outside Kirkuk's Rahimawa police station, killing himself and eight policemen and wounding more than 50 other people.
"Anyone who supports and cooperated with the infidels will be under threat of death," the group said. It threatened attacks on police checkpoints and warned, "We know all these [security] forces' movements."
"This is the last word for you, our Muslim brothers: Don't be a shield for the infidel Americans and sacrifice yourself for a handful of dollars," the leaflet said.
Elsewhere, a roadside bomb exploded today alongside a convoy of fuel tankers near Latafiyah, 25 miles south of Baghdad, witnesses said. A Saudi fuel truck was damaged and the driver injured, the witnesses said.