More than 250 bodies have been recovered from the rubble of a massive suicide bombing in northwestern Iraq, the deadliest single attack in the troubled country since the war began in 2003.

Rescue workers and relativespulled dozens of bodies Wednesday from demolished clay homes in theneighbouring villagesof Qataniya and Adnaniya, where fourvehicles blew up within minutes of each other on Tuesday.

At least one of the vehicles was a fuel tanker full of explosives, police said.

The blasts set shops ablaze, severely damaged nearby apartment buildings and flattened entire neighbourhoods. Health Minister Zayan Othman said more than 350 people were wounded in the blasts and warned that the death toll could rise.

"My friend and I were thrown high in the air. I still don't know what happened to him," Khadir Shamu, 30, told the Associated Press.

The BBC reported that the wounded streamed into area hospitals on Wednesday, as did potential blood donors looking to help. In one hospital,a bridetold reporters that her new husband and nine of his family members had been killed in the explosions.

The devastating strikestruck villages that are home to the Yazidi community, an ancient Kurdish sect that worships an angel figure that some Muslims and Christians consider to be the devil. The Yazidi community, located near the Syrian border, has been attacked by Muslim extremists before.

U.S. military officials were quick to condemn Tuesday's attack.

"This is an act of ethnic cleansing, if you will, almost genocide, when you consider the fact of the target they attacked," U.S. army Maj. Benjamin Mixon, the commander of U.S. forces in northern Iraq, told CNN.

With the death toll hitting 250 on Wednesday, theincident officially became the largest loss of life in an Iraqi attack since the 2003 U.S. invasion, surpassing a Nov. 23 bombing thatkilled 215 people and devastated Sadr City, a Shia neighbourhood in Baghdad.

Al-Qaeda blamed

No one claimed responsibility forTuesday's suicide bombings, but Dakhil Qassim, the mayor of the nearby town of Sinjar, blamedal-Qaeda, citing what he said were Kurdish government intelligence reports.

He said the bombings intended to kill "poor Yazidis who have nothing to do with the armed conflict," and added that al-Qaeda militants were "very active" in the area near the Syrian border.

A U.S. spokesman in Iraq also pointed to al-Qaeda.

"The car bombs that were used all had the consistent profile of al-Qaeda in Iraq violence," Brig. Gen. Kevin Bergner told reporters in Baghdad.

Iraq officials fear thesurge of U.S. troops in the city of Baghdad is pushing extremists to launch attacks in more remote parts of Iraq.

Difficult to curb violence

Yahid Said, who researches global governance at the London School of Economics, said the attack shows how difficult it will be to curb violence in Iraq.

"It definitely signals the fact that no matter how much is invested in the surge and other efforts, it's very difficult to control that territory of Iraq and to stop terrorists from inflicting damage," he told CBC News.

U.S. Gen. David Petraeus said the attack shows that the U.S. cannot too quickly withdraw the 30,000 additionalsoldiers sent to Iraq in early 2007, boosting the total U.S. contingent in the country to roughly 145,000 soldiers.

Petraeus said he will recommend that the U.S. Congress withdraw troops slowly through to next summer so that the U.S. doesn't lose "the gains we have fought so hard to achieve."