A spokesman for the U.S.-led coalition said Friday the airstrikes in Nuristan province hit militants who earlier attacked a U.S. military base with mortars.
The helicopters identified the militants' firing positions, tracked them down and destroyed the vehicles they were traveling in, said 1st Lt. Nathan Perry.
"These were combatants. These were people who were firing on us," Perry said. "We have no reports of noncombatant injuries."
He gave no account of casualties in the vehicles.
Nuristan's Gov. Tamim Nuristani said, however, 22 civilians were killed in the Waygal district of Nuristan province. "This afternoon (Friday), two civilian vehicles were hit by airstrikes," Nuristani said over the phone.
Among those killed were a woman and a child. All 22 dead bodies were brought to a provincial hospital, Nuristani said. Seven other people were wounded.
"Last night, the opposition fired rockets at the (U.S.) base ... and today this incident happened," said Nuristani, speaking from Kabul.
The military base is 6 miles away from the place where the airstrikes happened, Nuristani said.
It was impossible to independently verify any of the claims because of the remoteness of the area.
In other violence, gunmen lobbed a grenade and sprayed a police checkpoint with gunfire in the southern Kandahar province, killing eight officers, said provincial police chief Sumanwal Matiullah.
Overall, more than 8,000 people were killed in insurgency-related attacks in Afghanistan last year - the most since the 2001 U.S.-led invasion. Violence has claimed more than 2,100 lives so far this year.