DAMASCUS, Syria - U.S. military helicopters attacked an area along Syria's border with Iraq on Sunday, killing eight people, the Syrian government said.

The Syrian report comes just days after the commander of U.S. forces in western Iraq told reporters that American troops were redoubling efforts to secure the Syrian border, which he said was an "uncontrolled" gateway for fighters entering Iraq.

A government statement carried by the official Syrian Arab News Agency said Sunday's attack was on the Sukkariyeh farm near the town of Abu Kamal, eight kilometres inside the Syrian border. Four helicopters attacked a civilian building under construction, firing on the workers inside, shortly before sundown, the statement said.

The U.S. military in Baghdad did not immediately respond to a request for comment.

The area is near the Iraqi border city of Qaim, which had been a major crossing point for fighters, weapons and money coming into Iraq to fuel the Sunni insurgency.

Iraqi insurgents seized Qaim in April 2005, forcing U.S. marines to recapture the town the following month in heavy fighting. The area became secure only after Sunni tribes in Anbar turned against the rebels in late 2006 and joined forces with the Americans.

On Thursday, U.S. Maj.-Gen. John Kelly said Iraq's western borders with Saudi Arabia and Jordan were fairly tight as a result of good policing by security forces in those countries but that Syria was a "different story."

"The Syrian side is, I guess, uncontrolled by their side," Kelly said. "We still have a certain level of foreign fighter movement."

He added that the U.S. was helping construct a sand berm and ditches along the border.

"There hasn't been much, in the way of a physical barrier, along that border for years," Kelly said.