US and Afghan forces attacked a clinic in eastern Afghanistan where a Taliban leader was being treated for injuries he sustained last week, Nato has said.
They were fired upon when they neared the clinic in the Sar Hawza district of Paktika province, and responded by ordering helicopter strikes.
The troops first made sure there were no civilians inside, Nato added.
Nato said one soldier was killed and seven gunmen were arrested, but local officials said 12 militants had died.
Hamidullah Zhwak, a spokesman for Paktika's governor, said the Taliban commander had been wounded in clashes last Thursday, when Afghans voted in presidential and provincial elections.
He and three other wounded Taliban had been brought to the clinic at noon on Wednesday, shortly after which the Nato-led International Security Assistance Force (Isaf) was tipped off, he said.
Mr Zhwak said militants in a tower near the clinic had opened fired as the troops approached and that the gun battle had lasted five hours.
"After ensuring the clinic was cleared of civilians, an AH64 Apache helicopter fired rounds at the building, ending the direct threat and injuring the targeted insurgent in the building," Nato said on Thursday, adding that there were no civilian casualties.
A blast in Kandahar on Wednesday night which set a wood shop on fire caused no casualties, the AP news agency reported.
The explosion came one day after a massive explosion in Kandahar killed 43 people in Afghanistan's deadliest bombing for a year.