Zabiullah Mujaheed, a Taliban spokesman, claimed responsibility for the attack. After the blast, some 100 Taliban fighters fired at the coalition troops for several hours, briefly taking over two of their checkpoints, Mujaheed said.

Campbell denied the Taliban ever took over any checkpoints.

Zawak said that 32 insurgents were killed in the airstrikes and that authorities have already recovered 16 bodies. Mujaheed said five insurgents were killed and three were wounded.

It is impossible to independently verify Zawak's and Mujaheed's claims because the base is in a remote area.

Saturday's attack happened in the same province where an American soldier and three Afghans were believed captured by insurgents Tuesday.

U.S. troops continued looking for the soldier, Navy Chief Petty Officer Brian Naranjo said Friday. The military has not publicly identified him.

No immediate claim of responsibility was made by any insurgent group for the missing soldier or Saturday's attack.

Taliban faction led by Sirajuddin Haqqani operate in the area where the attack took place. The U.S. has accused Haqqani of masterminding beheadings and suicide bombings, including the July 2008 attack on the Indian Embassy in Kabul that killed 60 people.

In southern Afghanistan, meanwhile, a roadside bomb Saturday killed seven policemen in Kandahar province, the Interior Ministry statement said. Another two Afghan soldiers died in a separate blast in Helmand province's Musa Qala district also Saturday, the Defense Ministry said.