U.S.-led coalition and Afghan forces killed more than 15 insurgents during a hunt for inmates who fled prison after a sophisticated Taliban attack that set hundreds free, while Afghan forces recaptured 20 prisoners, officials said Sunday.

The U.S. said it couldn't immediately confirm that any of the 15 killed were escaped prisoners. Five militants were also captured during the Saturday operation, it said.

The provincial police chief of Kandahar province has said 870 prisoners — including some 400 Taliban militants — escaped from the Kandahar prison during a coordinated assault on the facility by dozens of insurgents late Friday.

The chief, Sayed Agha Saqib, said Sunday that Afghan police and army soldiers have recaptured 20 prisoners, including seven former Taliban inmates.

The coalition said the 15 insurgents it killed were in a farming compound in Kandahar province and that the combined forces used air strikes to destroy it after insurgents fired at them.

NATO has said the prison break was a tactical success for the Taliban but would not have a long-term or large impact on the Afghan conflict. However, Afghan officials have warned that dangerous members of the militia are now free, and that the prison attack essentially boosted the insurgents' ranks by 400.

In neighboring Helmand province, meanwhile, the U.S. coalition said "several" militants were killed during an operation targeting a Taliban weapons smuggler in Garmser, where hundreds of U.S. Marines have been operating the last two months.

Militants in a compound fired on the coalition forces, who responded with gunfire and air strikes, the coalition statement said. Troops found several weapons and 250 pounds of narcotics during a search after the fight. Garmser is filled with opium poppy fields and is a major narcotics trafficking point.

Also in Helmand, a roadside bomb killed the district police chief of Nad Ali, said Mohammad Hussein Andiwal, the provincial police chief. The Nad Ali district chief was wounded in the attack, he said.

Andiwal said the road where the explosion happened is usually patrolled by NATO and Afghan forces.