BAGHDAD, Iraq (AP) – A farmer claiming to have witnessed an attack on a US military checkpoint said Sunday that insurgents swarmed the scene, killing the driver of a Humvee before taking two of his comrades captive.

The White House promised to do everything it could to find the soldiers and said it had a message for those who may have taken the two men: “Give them back.”

US troops, backed by helicopters and warplanes, fanned out across the ‘Triangle of Death’ south of Baghdad searching for the missing servicemen.

At least four raids had been carried out, but the captives were not found, the military said.

Another local resident said the soldiers were searching houses on Sunday and promising a US$100,000 reward for any information leading to the missing soldiers.

A US military spokesman, Major General William Caldwell, said Saturday a dive team also was searching for the men, whose checkpoint was near a Euphrates River canal not far from Youssifiyah, 20 kilometres (12 miles) south of Baghdad.

The Sunni region is the site of frequent ambushes of U.S. soldiers and Iraqi troops.

Ahmed Khalaf Falah, a farmer who said he witnessed the attack Friday, said three Humvees were manning a checkpoint when they came under fire from many directions.

Two Humvees went after the assailants, but the third was ambushed before it could move, he told the Associated Press.

Seven masked gunmen, including one carrying what Falah described as a heavy machine gun, killed the driver of the third vehicle, then took the two other US soldiers captive, the witness said.

His account could not be verified independently.

Iraqi Foreign Minister Hoshyar Zebari also said the soldiers appeared to have been taken prisoner by insurgents.

“Hopefully they will be found and released as soon as possible,” he said on CNN’s Late Edition.

The US military said Sunday it was continuing the search.

“Coalition and Iraqi forces will continue to search everywhere possible, uncovering every stone, until our soldiers are found, and we will continue to use every resource available in our search,” it said.

White House spokesman Tony Snow also said he had no new information about the search and could not confirm reports that the two men were abducted. But he told Fox News Sunday that he would tell anybody who was holding them to “give them back.”