Elements of the US Army's 3rd Infantry Division and the 1st Marine Expeditionary Force swept across the border Thursday, hours into the campaign to oust Saddam for harboring suspected weapons of mass destruction.

Captain Andrew Valles, spokesman for the infantry division's First Brigade, said that according to the reports he had received, "there was little to no resistance" from the Iraqis on the ground.

Officers with the division reported sporadic encounters with the Iraqis. They said an M1-A1 tank and three Bradley Fighting Vehicles opened fire on an Iraqi observation post, killing three men.

"As for any soldiers, we didn't see anybody," said Staff Sergeant James Currence, a tank commander.

Sergeant First Class Melvin Green said his tank and another M1-A1 took out two T-72 tanks, the most modern in Iraq's armed forces. "I saw the turret pop off," he said of his encounter with the T-72.

WAR.WIRE