Sectarian gunmen disguised in military fatigues shot dead 18 Shiite Muslim men on Tuesday in a usually quiet region of Pakistan that neighbours the former Taliban stronghold of Swat.
The attackers flagged down four buses, climbed on board asking passengers whether they were Shiite or Sunni Muslim, then dragged out the Shiites and shot them dead in cold blood, police said.
Another eight people were wounded, including two women and three children, in the attack in northern Kohistan district near the town of Harban, 130 miles (210 kilometres) north of the capital, said Kohistan police chief Mohammad Ilyas.
"The motive was sectarian. The gunmen were wearing army uniform, they were disguised as soldiers," Ilyas told AFP.
"They checked the identity of the passengers, got the Shiites off the vehicles and shot them dead," Ilyas said. "The dead were all male."
Kohistan administration chief, Aqal Badshah, said 18 people were killed by eight attackers armed with Kalashnikovs and wearing military dress.
Human rights groups have heavily criticised the Pakistani government for failing to crack down on sectarian violence between the country's majority Sunni and minority Shiite Muslim communities that has killed thousands.
Local MP Abdul Sattar Khan linked the ambush to the murder of two Sunni Muslims a few days ago in Gilgit.
"The people of the area had vowed they would take revenge," Khan told AFP by telephone.
Authorities had been initially slow to confirm the motive and insisted Islamist militants were not active in the area. Kohistan borders Swat, where Pakistan in 2009 managed to put down a two-year Taliban insurgency.
Three bombs have targeted Pakistan's northwest in recent days, raising fears that violence linked to a Taliban insurgency directed against a government allied to the US-led war against terror is again on the rise.
More than 530 bomb attacks have killed around 4,900 people across Pakistan since government troops in July 2007 stormed a mosque in Islamabad where Islamist extremists were holed up, provoking a local Taliban-led insurgency.
Source: AFP Global Edition