Three policemen have been shot dead near the Pakistani capital Islamabad.

A police spokesman said the bodies of the dead men were discovered early Sunday.

He said the men were apparently shot in their sleep, each by a single bullet to the head.

The men were guarding a railway bridge in Hasan Abdal, a town 40 kilometers west of Islamabad.

The police spokesman refused to comment on whether the slayings were a criminal act or an attack linked to the Taliban, who frequently target police and security forces.   

Some information for this report was provided by AFP and AP.