BAGHDAD — Four suicide bombers drove trucks packed with explosives into a complex housing members of a small religious sect in northern Iraq on Tuesday, killing at least 175 in the deadliest attack on civilians in the country in nearly a year.
The simultaneous blasts targeting the Yazidi community in Qahtaniya, about 70 miles west of Mosul, also injured 200 people and further damaged ethnic cohesion in a country beset by sectarian conflict.
Earlier Tuesday, a suicide bomber drove a truck laden with explosives onto a key bridge linking Baghdad with vital northern oil fields. At least 10 people died when the concrete span plunged into the murky waters of a canal linking the Tigris and Euphrates rivers.
Dozens of Iraqis died in other incidents across the country. Six U.S. troops also died, including five who were killed in a helicopter crash in Al Anbar province in the west.
And in a challenge to U.S. and Iraqi efforts to quell rampant violence, scores of gunmen dressed as Iraqi soldiers kidnapped five senior Oil Ministry officials in broad daylight, using 17 official government vehicles to seize them at their heavily fortified central Baghdad compound.
The attack in northwestern Iraq took the Yazidi community by surprise and spurred accusations of religious and ethnic intolerance.
Some Kurds believe that the Yazidi people, most of whom are Kurds but are neither Muslim nor Christian, are members of a demonic cult. The sect has faced persecution under a succession of rulers in Iraq.
The bombings came several months after gunmen dragged 21 members of the sect off a bus and killed them, apparently in retaliation for the stoning death of a Yazidi woman who converted to Islam and had a love affair with a Sunni Muslim man. She was killed by fellow Yazidis.
"There is no justification for this," said Aydan Shikh, a 33-year-old Yazidi activist surveying the devastation after the bombings, which left apartment buildings and stores ablaze. "What crime have the Yazidis committed to deserve this?"
Subhee Abdullah, a shop owner who was about to close up when the attacks occurred, described a scene of panic and chaos. Yazidis, maimed and bleeding, crouched in hiding, fearful that more blasts were coming.
"I saw people drowning in their own blood," the 50-year-old said. "More people are sure to die."
The U.S. government condemned the attack.
"Extremists continue to show to what lengths they will go to stop Iraq from becoming a stable and secure country," the White House said in a statement. "We will continue to work with the Iraqi government and the Iraqi security forces to stabilize the country and beat back these vicious and heartless murderers."
The death toll was the highest in a single attack since a series of car bombings killed 205 people in the Sadr City neighborhood of Baghdad in November 2006.
Five U.S. troops died when their CH-47 Chinook aircraft went down shortly after takeoff from the Taqaddum air base near Fallouja on a routine post-maintenance test flight, the military reported. Another soldier was killed in combat in west Baghdad. The deaths brought the number of U.S. service personnel killed in Iraq since the March 2003 invasion to at least 3,699, according to the website icasualties.org, which tracks military casualties.
The bridge bombing in Taji, north of Baghdad, severed the main transport link northward from the capital. There are no convenient alternatives to driving from the capital to Mosul or Kirkuk. Authorities were planning to use a nearby railway bridge for pedestrian traffic, shuttling travelers from either side of the canal to their destinations by bus.
Despite the intensified crackdown by U.S. and Iraqi forces, militants continued to carry out attacks across Iraq.
Militants killed the pregnant wife of an Iraqi policeman, his brother and 12-year-old son in Suwayrah, 30 miles southeast of Baghdad, and four people were gunned down in a Shiite Muslim village in Diyala province, where 16,000 U.S. and Iraqi troops deployed this week to beef up security.
In Kirkuk, a car bomb exploded near a passing police car, killing one officer and wounding four, said Lt. Marwan Khalil of the city's force. Seventeen civilians also were hurt.
Fifteen bodies with bullet wounds were found in Baghdad early Tuesday, presumed victims of death squads.
A U.S.-led offensive launched this week is targeting fighters with Al Qaeda in Iraq and Shiite death squads.
Military officials said the operation netted 16 suspected terrorists Tuesday, but it also appeared to have inflicted civilian casualties. Witnesses reported that a family of four, including a 3-year-old, died in an airstrike overnight on their apartment building in Sadr City as they slept on the roof.
The push against elements of Shiite cleric Muqtada Sadr's Al Mahdi militia in Sadr City also killed four radicals, the U.S. military said. Twelve others were detained.
Iraqi Prime Minister Nouri Maliki continued efforts to rescue his beleaguered Shiite-led government.