Islamabad: Militants clad in military uniforms intercepted a convoy of buses and gunned down 18 minority Shia men on Tuesday in a northern Pakistan region that borders the former Taliban stronghold of Swat.

Eight others were injured in the attack, for which the banned Jundullah group has claimed responsibility.

Two women and three children were among the injured, officials said.

About 10 to 15 gunmen stopped three buses near Harban village in Kohistan district of Khyber-Pakhtunkhwa province, about 200 km from Islamabad, and shot the Shias after ascertaining their identity.

The buses were going from the garrison city of Rawalpindi to Gilgit, which has a sizeable Shia population.

The buses stopped near Harban as the road was blocked with large stones.

The gunmen then entered the vehicles and began asking the passengers whether they were Shias or Sunnis.

They thoroughly questioned the passengers and even checked their identity cards, officials said.

The gunmen forced the Shia men out of the vehicles and made them stand in a line before opening fire, local lawmaker Abdul Sattar Khan and other officials told the media.

Some police officials said the gunmen were wearing army uniforms. Over two dozen other passengers were spared.

Police officials said all the dead were Shia men and that the buses were passing through an area dominated by Sunnis.

The injured were taken to a hospital in Chilas town. Most of them were in a serious condition, officials said.

Commander Ahmed Marwat of the outlawed Jandullah group claimed responsibility for the attack in phone calls to journalists.

He said those executed in the incident were "Shia infidels".