Suspected Taliban militants attacked police posts in southern Afghanistan, sparking clashes and NATO airstrikes that left 25 civilians dead, a senior police officer said Friday.

The militants attacked police and used civilian houses for cover in Gereshk district of Helmand province late Thursday, said Mohammad Hussein Andiwal, provincial police chief.

NATO responded by calling in airstrikes, which killed 20 suspected militants, but also 25 civilians, including nine women, three babies and the mullah of a local mosque, he said.

NATO said the aircraft struck after insurgents attacked troops from its International Security Assistance Force nine miles northeast of Gereshk town.

"A compound was assessed to have been occupied by up to 30 insurgent fighters, most of whom were killed in the engagement," a NATO statement said.

"We are concerned about reports that some civilians may have lost their lives during this attack," said Lt. Col. Mike Smith, an ISAF spokesman.

Taliban used at least two civilian compounds for cover during the clashes, which lasted into early Friday, Andiwal said.

"NATO was targeting the areas where the fire was coming from ... and two compounds were completely destroyed, and the families living in those compounds were killed," he said.

Villagers loaded the victims' bodies onto tractor trailers to take them to the provincial capital, Lashkar Gah, to prove they were innocent victims, but police stopped them, Andiawal said.

Smith said "it was the insurgents who initiated this attack, and in choosing to conduct such attacks in this location and at this time, the risk to civilians was probably deliberate."

"It is this irresponsible action that may have led to casualties," he said.

On Monday, Afghan officials had said that more than 100 people, including militants, civilians and police, died in three days of fierce clashes between NATO forces and Taliban fighters, also in southern Afghanistan.

A senior Afghan Defense Ministry official has said that civilian deaths are the main concern of Afghans, and President Hamid Karzai has repeatedly called for foreign troops to do more to prevent civilian casualties.