U.S. officials said on Thursday there was little hope of finding anyone still alive in the rubble of scores of houses destroyed by suicide bombers in northern Iraq.

Possible death tolls given by officials from the apparently coordinated truck bombings of two remote villages inhabited by members of the minority Yazidi sect ranged from 175 to as high as 500. Hundreds more were wounded.

Rescuers dug through the rubble of bomb-flattened buildings throughout Wednesday in scenes reminiscent of an earthquake zone. Bodies covered by blankets were laid in the street and outside a municipal building.

Major Rodger Lemons, operations officer for a U.S. brigade in the area, said on Thursday rescue efforts were beginning to wind up. About 600 people had been made homeless, he added.

"My assessment is there's probably no one left alive in the rubble," he added. "We've transitioned through to a clean-up phase."

The U.S. military has said al Qaeda is the prime suspect for the attack on the Yazidis, seen by Sunni militants as infidels.

Lemons said it appeared two garbage trucks packed with explosives had been driven into each of the two villages, Kahtaniya and al-Jazeera.

In al-Jazeera, Iraqi security forces shot and killed the driver of one truck before it reached the village. Both trucks detonated in Kahtaniya village, he said.

The bombings were the worst coordinated attack in Iraq since November 2006, when six car bombs in different areas of Baghdad's Shi'ite Sadr City killed 200 people and wounded 250. That was the biggest attack since the U.S.-led invasion in 2003.


TOLL MAY NEVER BE KNOWN

Nineveh province governor Duraid Kashmoula said the blasts in Kahtaniya and al-Jazeera had levelled hundreds of houses, mostly made of clay, and buried entire families. He put the death toll at 220.

Zairyan Othman, minister of health in neighbouring Kurdistan, Iraq's semi-autonomous Kurdish region, said 205 were killed and 235 wounded. Iraq's Health Ministry said on Thursday more than 150 were killed and more than 200 wounded.

Kifah Mohammed, director of Sinjar hospital in the area of the bombings, said the toll could be 500, with 400 wounded. Other health officials in the area said the 500 included dead and wounded.

The U.S. military said between 175 and 180 people had probably been killed. "I don't know if we'll ever get to a point where we'll have an exact figure," Lemons said.

Deputy Prime Minister Barham Salih flew to the region on Thursday to inspect the devastated villages.

U.S. officials had said they feared al Qaeda would launch a large-scale attack on civilians before mid-September, when the U.S. Congress is due to receive a military and political progress report on Iraq.

U.S. forces launched an airborne assault on a compound south of Baghdad early on Thursday, the first strike in a major new offensive that is part of a countrywide push announced this week against both Sunni Arab and Shi'ite militants.

Yazidis are members of a pre-Islamic Kurdish sect in northern Iraq and Syria who say they are persecuted because of their beliefs.

In Baghdad, a car bomb in a parking lot killed nine people and wounded 17 on Thursday near al-Russafi Square in the heart of the capital.