Afghan and U.S. troops backed up by American aircraft fought suspected Taliban rebels in southern Afghanistan on Saturday, leaving one U.S. service member and an unknown number of militants dead, officials said.

A second U.S. service member and an Afghan soldier were wounded in the fighting in Helmand province's Sangin district, a hotbed of insurgency and the booming drug trade, a U.S. military statement said.

American war planes dropped 11 guided bombs on about 20 militants taking part in the clash, the U.S. military said. "Some Taliban have been killed, but we don't know how many," said Afghan army commander Gen. Rahmatullah Raufi.

The slain U.S. service member's name was withheld pending notification of relatives. His death brought to 222 the number of U.S. service members killed in and around Afghanistan since the ouster of the Taliban regime in 2001.

"Coalition forces will continue to attack these enemies of Afghanistan until the district and province are safe and secure," said U.S. commander Maj. Gen. Benjamin C. Freakley.

The wounded troops were evacuated to a coalition base for treatment.

Fighting has spiked in southern Afghanistan in the past year, leaving swaths of it off-limits to aid workers and raising concerns for this country's fragile democracy.