Islamabad  - Four Shiite Muslims were gunned down on Tuesday in Pakistan's troubled North-West Frontier Province (NWFP), police said.

The incident occurred in the sectarian violence-prone town of Hangu, located some 100 kilometres south-west of provincial capital Peshawar.

"Gunmen fired a volley of shots near a market, killing four people, including three family members," a duty officer said.

Tension ran high in the area where business centres were closed in anticipation of backlash.

Police did not confirm the attack was sectarian, but the town's history is tainted with violent clashes between the majority Sunni and minority Shiite Muslims.

Tuesday's attack in Hangu came one day after a bomb explosion at a Shiite mosque in another NWFP town of Dera Ismail Khan killed four people, including a child. (dpa)