The airstrikes occurred in southern Helmand province after rebels had pinned down coalition ground troops with rocket and small-arms fire, the military said in a statement.
"Initial battle-damage assessments indicate 15 to 20 enemies died and an enemy vehicle was destroyed," it said. No U.S. soldiers were injured.
"When these criminals engage coalition forces, they do so at considerable risk," said Lt. Col. Jerry O'Hara, a U.S. military spokesman. He vowed to "destroy those that stand against Afghan and coalition forces at every opportunity."
The fighting is the latest in a string of attacks and battlefield engagements across the south that have raised fears that Taliban rebels and their al Qaeda allies are regrouping.
About 260 suspected rebels and 29 U.S. troops have been killed in the surging violence since March, according to Afghan and U.S. officials. About three dozen Afghan police and soldiers have also died in that time, as have more than 100 civilians.
Early Sunday, three rockets smashed into the southern Afghan city of Kandahar, jolting residents but causing no casualties,
One of the rockets hit an empty lot near the former home of fugitive Taliban leader Mullah Mohammed Omar which now houses U.S. special forces troops, said Gen. Salim Khan, the deputy police chief. The other two hit elsewhere in the city.
Khan blamed Taliban rebels for the attack, which occurred at about 3 a.m.
"The one rocket hit right next to Mullah Omar's home, and two other rockets hit fields in Kandahar city," said Khan. "The Taliban did this. Nobody else would do such a thing."
U.S. troops cordoned off the area next to Mullah Omar's old home, keeping residents and journalists a good distance away.