Afghan officials say militants in southern Helmand province poisoned a group of policemen and then attacked their police post, leaving six people dead.

The officials say the late-night assault occurred at Helmand's Nahri Sarraj district.

Police and local officials say the militants poisoned the policemen's food then started a gunfight with them, killing four officers and two civilians.

The Taliban claimed responsibility for the Monday attack.

In other violence, NATO said three of its service members died in eastern Afghanistan Tuesday. A NATO statement said two soldiers were killed in an insurgent attack and a bomb explosion, while the third died as a result of a non-battle-related injury.

The nationalities of the soldiers were not released.