Groups of militants began launching attacks Wednesday on a coalition reconnaissance patrol in the south, using rocket-propelled grenades, machine guns and small arms fire, the coalition said Friday.
Coalition troops "returned fire with small arms and close air support," destroying several vehicles and killing more than three dozen insurgents, the statement said. Capt. Christian Patterson, a coalition spokesman said Friday night that the operation was still ongoing. He would not disclose the exact location of the clashes.
Southern Afghanistan is the center of a six-year-old Taliban-led insurgency in Afghanistan that is gaining strength and spreading to the east. At least 93 U.S. troops have died in the country so far this year, a pace that would make 2008 the deadliest for American forces since the 2001 invasion.
In a separate incident, militants attacked a NATO patrol with a roadside bomb and small arms fire in eastern Afghanistan on Friday, killing two troops, the alliance said in a statement. NATO did not provide further details on the attack and did not release the nationalities of those killed. But most of the troops in the area are American.
The U.S.-led coalition in Afghanistan reported Friday an unusual operation involving dogs that were used to attack and help capture at least two suspected Taliban militants fleeing coalition forces.
The dogs bit two of the fleeing militants in the operation Thursday in eastern Paktika province, which targeted a wanted Taliban subcommander, a coalition statement said.
"Two militants attempted to flee and were pursued by coalition military working dogs," the statement said. "Both militants received dog-bite injuries, one of which required treatment on scene by coalition medical personnel."
Reports of using dogs to attack militants in Afghanistan are rare, though dogs employed by the coalition have been seen at checkpoints and are used to sniff for explosives.
In Islamic tradition, dogs are shunned as unclean and dangerous. But dog-fighting is a popular sport in Afghanistan, a conservative Muslim country.
Eight suspected insurgents were detained in the operation, including the two bitten by the dogs.
More than 3,200 people have died in violence across Afghanistan so far this year, according to an Associated Press tally of figures provided by Afghan and Western officials.