KANDAHAR AIRFIELD, Afghanistan — Coalition forces launched a major offensive in northern Helmand province Saturday, using a fleet of helicopters to drop thousands of troops onto rooftops in the city of Sangin before dawn.

At least 10 Taliban fighters were killed in the initial attack, according to coalition spokesman Maj. Scott Lundy of the Canadian army. U.S., British and Canadian forces are taking part in the ongoing operation.

“The coalition targeted several known Taliban strongholds, so the goal is to move in, remove the Taliban and continue with local engagement afterwards … to see what else needs to be done,” Lundy said.

U.S. officials would not release the number of American troops involved. No coalition forces were seriously injured in the initial phase of the operation.

Hundreds of Taliban fighters were believed to be in the area, and the coalition troops will continue to comb the area “until we can create a security pocket there,” Lundy said.

Sangin sits about 70 miles east of Kandahar Air Base, in southern Afghanistan. Lundy called the region a strategic crossroads for enemy fighters.

“It’s a major throughway for the region, and economically the poppy revenues they get from the area allow them to continue operating,” he said.

No civilian casualties were reported from the fighting, Lundy said.

On Friday night, Afghan National Army and coalition forces sparred with dozens of Taliban fighters in three separate battles in Uruzgan province, northeast of Helmand. A spokesman for Combined Force Command Afghanistan said 31 enemy fighters were killed in the actions.

U.S. officials said the goal there was the same — to root out enemy operations in the region. No civilian casualties were reported.

Lt. Col. Paul Fitzpatrick, spokesman for Combined Joint Task Force 76, said U.S. forces will continue to “disrupt and hunt down extremists operating in southern Afghanistan.”