BAGHDAD -- Thirty-one U.S. troops were reported killed in a helicopter crash and five more died in insurgent attacks Wednesday in the deadliest day for American forces since they invaded Iraq 22 months ago.
The heavy U.S. toll came amid a series of guerrilla bombings and raids that killed 10 Iraqis in a campaign to sabotage Sunday's landmark election -- a cornerstone of U.S. plans in Iraq.
CNN, quoting the U.S. military, reported 31 Marines died when their transport helicopter went down in the deserts of the restive Anbar province of western Iraq.
The military confirmed casualties to reporters but gave no figures, as search and rescue teams scoured the area. The cause of the crash was not immediately known.
Four U.S. Marines were killed in action in Anbar province, and an American soldier was killed in a rocket-propelled grenade attack north of Baghdad, U.S. officials said.
The latest surge of insurgent attacks appeared aimed at sowing panic even as the U.S.-backed interim government vowed stringent measures to safeguard the election, Iraq's first since the fall of Saddam Hussein in April 2003.
In a closely coordinated attack, three suicide car bombers hit the town of Riyadh, a Sunni Arab area southwest of the northern city of Kirkuk.
Two explosives-laden cars blew up simultaneously close to an Iraqi army post and police station and a third vehicle detonated minutes later on a nearby highway, a local police chief said.
Four Iraqi policemen, two Iraqi soldiers and three civilians were killed, and at least 12 people were wounded, police said.
Shortly after the blasts, a U.S. combat patrol heading to the scene came under small arms fire and two U.S. soldiers were lightly wounded, the military said.
The previous deadliest day for U.S. forces was March 23, 2003, the third day of the war, when 28 U.S. soldiers died mostly in fierce fighting in southern Iraq.
STRING OF ATTACKS
Police in Baquba, a mixed Shi'ite and Sunni town 65 km (40 miles) north of Baghdad, said one Iraqi policeman was killed and at least eight people were wounded when gunmen fired on the local offices of three parties contesting the polls.
Sunni insurgents have repeatedly targeted the country's fledgling security forces in the countdown to the election, accusing them of collaborating with U.S.-led occupiers.
Iraq's Shi'ite minority is expected to dominate the vote after decades of rule by Saddam's Sunni minority.
In the northern city of Mosul, a rebel stronghold that has seen persistent violence, a video filmed by insurgents showed three Iraqi men who had apparently been taken hostage and who said they worked for Iraq's electoral commission in the city.
On the video, a hooded insurgent carrying a pistol read out a statement as another masked guerrilla crouched with a rocket-propelled grenade launcher on his shoulder.
"We are mujahideen in the province of Nineveh. What they call elections have no basis in the Islamic religion and that's why we will hit all election centers," the statement said.
Several guerrilla groups in Iraq -- including militants loyal to Abu Musab al-Zarqawi, al Qaeda's leader in the country -- have declared war on Sunday's elections, vowing to attack polling stations and kill those who dare to vote.
The government plans extraordinary security measures, including closing Baghdad airport and land borders over the election period, extending night curfews in cities and banning cars from roads on election day. Zarqawi, a Jordanian with a $25 million bounty on his head, says the election is a plot by Washington and Iraqi Shi'ite allies against Sunni Arabs, who now fear being marginalized.
Iraq's Shi'ites, oppressed under Saddam, strongly support the elections. A list of candidates dominated by Shi'ite Islamists and drawn up with the guidance of revered cleric Ayatollah Ali al-Sistani is expected to win the most votes, cementing the newfound political power of Shi'ites.
But many Sunni Arab parties will boycott the polls, saying the insurgency raging in Iraq's Sunni heartlands will prevent their supporters from voting and skew the results.
Tension between Shi'ite and Sunni Arabs has been stoked by a series of bomb attacks on Shi'ite targets, raising fears of sectarian conflict.
Insurgents have also assassinated several leading officials. Tuesday a top Baghdad judge was killed along with his son in an ambush as they left home during morning rush hour.
© Reuters Ltd 2005