An Al-Qaida group is warning people to stay away from the polls.
BAGHDAD, Iraq (AP) -- A U.S. helicopter crashed in a desert sandstorm in the early morning darkness Wednesday, killing the 30 Marines and one Navy sailor aboard. Six other troops died in insurgent ambushes in the deadliest day for Americans since the Iraq war began nearly two years ago.
Only days before Iraq's crucial elections Sunday, militants set off at least eight car bombings that killed 13 people and injured 40 others, including 11 Americans. The guerrillas also carried out a string of attacks nationwide against schools that will serve as polling centers.
In Washington, President Bush called on Iraqis to defy terrorism and go to the polls despite relentless insurgent attacks. He said it was a "very discouraging" day when the U.S. death toll for the war rose above 1,400.
The CH-53E Super Stallion was carrying personnel from the 1st Marine Division on a security mission in support of the election when it went down about 1:20 a.m. near the town of Rutbah, about 220 miles west of Baghdad, the military said.
The crash occurred during severe weather, but its cause was still under investigation, said Army Gen. John Abizaid, chief of U.S. Central Command. An Accuweather map showed sandstorms Wednesday in the western region of Iraq near the Jordanian border where the crash took place.
A search and rescue team was at the site. The victims were 30 Marines and one sailor, said Lt. Gen. John Sattler, the top Marine commander in Iraq -- the most American service members to die in a single episode since the March 2003 invasion of Iraq.
The previous deadliest encounter for U.S. troops was also a helicopter crash: a November 2003 collision of two Black Hawk helicopters that killed 17. Before Wednesday's bloodshed, the most Americans killed in one day came on the invasion's third day -- March 23, 2003 -- when 28 troops were killed during the U.S. military's drive to take Baghdad and topple Saddam Hussein.
The U.S. military has not seen such a high loss of life in one day in 15 years -- since an explosion ripped through a gun turret on the USS Iowa during a training exercise in the Caribbean in April 1989, killing 47 sailors.
Iraqi security forces and civilians have borne the brunt of violence in Iraq, with bombings often killing scores of people at a time. More than 180 people were killed March 2, 2004, during a string of suicide attacks at Shiite shrines in Karbala and Baghdad.
Violence has increased ahead of Sunday's election, which will create a 275-member National Assembly and regional legislatures. Sunni Muslim extremists have threatened to sabotage the election, and many Sunni clerics have called for a boycott because of the presence of U.S. and other foreign troops.
The group calling itself Al-Qaida in Iraq warned people to stay away from the polls, threatening attacks. "Oh people, be careful. Be careful not to be near the centers of infidelity and vice, the polling centers ... Don't blame us but blame yourselves" if harmed," a Web statement issued in the group's name said.
In addition to Wednesday's crash deaths, four Marines were killed in fighting in Iraq's Anbar province.
A reporter embedded with those troops, Jim Dolan of WABC in New York City, said the deaths came when insurgents ambushed a Marine convoy leaving the town of Haditha, northwest of Baghdad, hitting a vehicle with a rocket-propelled grenade.
Also Wednesday, insurgents attacked a U.S. Army patrol near the northern town of Duluiyah, killing one soldier and wounding two others, and in the Baghdad area a roadside bomb killed another soldier and wounded two others, the U.S. command said.
The day's deaths brought to at least 1,409 the number of members of the U.S. military who have died in Iraq, according to an Associated Press count.
A string of political violence continued. Several schools slated to be used as polling stations were bombed overnight.
A suicide bomber detonated a fuel tanker at the offices of the Kurdistan Democratic Party in the town of Sinjar, southwest of Mosul, killing five and injuring at least 20 people, KDP officials said.
Earlier in the day, gunmen opened fire with machine guns on the local headquarters of the Patriotic Union of Kurdistan and the Communist Party in the city of Baqouba, north of Baghdad, killing a traffic policeman. The KDP and PUK are the two largest Kurdish groups in Iraq and have formed a coalition along with other Kurdish groups to run in the election.
Insurgents also set off three car bombs in rapid succession in the town of Riyadh, north of Baghdad, killing at least five people -- including three policemen.
Four American soldiers were injured in a car bombing Wednesday in Saddam's hometown of Tikrit, the U.S. command said. Another car bomb targeted a multinational forces convoy on the road to Baghdad's international airport, injuring four soldiers, the command said.
The attack temporarily closed the airport road, one of the country's most dangerous.
Another car bombing later hit the same airport road, and an eighth car bomb detonated prematurely 30 miles north of Baghdad, killing the two men in the car.