The commander of U.S. and NATO forces in Afghanistan has apologized on national Afghan television for an airstrike that took the lives of up to 27 civilians, the alliance said on Tuesday.

General Stanley McChrystal said that Sunday's airstrike in the Uruzgan province had been targeted against a group of vehicles carrying people that NATO mistakenly believed were militants. Four women and a child were among the dead.

It was the third case of international forces mistakenly attacking civilians in a week.

His comments translated into Dari and Pashto, McChrystal called the incident a "tragic loss of innocent lives".

"The International Security Assistance Force, while conducting a mission with Afghan security forces, launched an attack against what we believed to be a group of insurgents," he said. "We now believe the attack killed and injured a number of Afghan citizens."

"I have spoken with President Karzai and apologized to him and the Afghan people. I have instituted a thorough investigation to prevent this from happening again," he went on.

"I have made it clear to our forces that we are here to protect the Afghan people," he added.

Independent observers say NATO forces were responsible for some 500 deaths in Afghanistan in 2009, down 39% on 2008.

MOSCOW, February 23 (RIA Novosti)