A US helicopter crashed in Iraq, killing at least 12 on board, and five Marines died in a spate of attacks in the west of the country. The helicopter came down in a sparsely populated area of northern Iraq shortly before midnight, the military said yesterday. There were four crew and eight passengers on the manifest to take the flight, they said.

It was the worst incident of its kind since January last year, when a transport helicopter crashed close to the Jordanian border, killing 30 Marines and one sailor.

The Americans did not give a reason for the crash and said it was being investigated. The helicopter was a UH-60 Blackhawk, the most frequently used by the military to transport its 150,000 troops around the country.

The military also said five Marines were killed in and around the western city of Fallujah, a hotbed of the largely Sunni Arab insurgency trying to drive the Americans out of Iraq.

Three were killed in three attacks yesterday, all victims of small arms fire. The other two died on Saturday in two villages near Fallujah when their vehicles were hit by improvised bombs.

In Baghdad, US troops raided offices of the influential Muslim Clerics' Association, which opposes the US presence in Iraq. They blew doors off their hinges, ransacked the office and arrested five people, the association said.

Footage showed spent shotgun shells and special explosive charges lying on the ground of the offices, housed in a mosque complex. In one room, cupboards used to store the shoes of those attending prayer had what appeared to be Christian crosses scrawled on them.

US military spokesman Lieutenant-Colonel Barry Johnson said the troops had been reacting to a tip-off of "substantial terrorist-related activity" and rejected as "unbelievable" any suggestion they might have been responsible for the crosses.

The conclusion of a probe into Iraq's landmark election will be announced on Monday, the electoral commission said yesterday, in a sign that the final results of the contested poll could be out soon.

A separate team of international monitors also said its inspection of the December 15 election was going well and a report would be released "as soon as we can".

The electoral commission has been investigating complaints of ballot-rigging and other allegations of fraud made in the wake of Iraq's first vote for a permanent parliament since the fall of Saddam Hussein in April 2003.

The probe, called for by Sunni-backed and secular parties, has delayed the release of certified results and the formation of a new government in the violence-wracked country. Early results suggested that Shi'ite-backed religious parties and their Kurdish allies would be returned to power.

At a Press conference, the commission will announce "the conclusion of the investigation and the decisions of the Independent Election Commission of Iraq (IECI)," its Press office said.

Of some 1,800 complaints made, about 50 - the most serious - are directly connected to the election results. These so-called red complaints will be the focus of the briefing, an official involved in the process said.

PHOTO CAPTION

A U.S. UH-60 Blackhawk helicopter flies a medical evacuation mission over Baghdad, in this photograph obtained on April 3, 2005. (REUTERS)