US troops and government forces have killed 64 insurgents in southern Afghanistan, US military confirmed Thursday.

There have been 20 militants died in the battle Tuesday in Zabul province when warplanes attacked militants fighting US troops and Afghan police.

The number of death rose to 64 after troops found more bodies.

The attack began when an Afghan man complained to Afghan National Police officers of being beaten by a group of unknown individuals. The man led the Afghan National Army (ANA) forces andUS forces to the location of the beating where they came under small-arms fire.

ANA forces and US Soldiers cordoned off the insurgent forces byuse of small-arms fire and support from Coalition fixed-wing and rotary-wing aircraft.

It's the bloodiest fighting since August last year, when Afghantroops and US warplanes killed up to 70 militants in the southeastern province of Khost.