At least 11 people have been killed and several injured in a village near the city of Haripur in northwest Pakistan, after unidentified people indiscrimnately opened fire on a funeral procession.

Senior police officials in the district said they were investigating if the incident was linked to sectarian rivalry between two different groups of militant Muslims.

All hell broke loose in the otherwise peaceful district in north-western Pakistan, when the funeral procession was attacked by at least four persons using automatic guns.

Police officials said Muslim funeral services were under way in a local graveyard near the city of Haripur when it came under fire from two sides.

Several people were killed on the spot and many more were injured.

A number of injured later died of their wounds at a local hospital. Doctors said the condition of at least three of the injured was critical.

Police officials in Haripur said the firing incident was apparently linked to a long-standing dispute over a piece of graveyard land between two religious groups belonging to the majority Sunni and minority Shia communities.

All the victims of the incident were Sunni Muslims.

There have been several incidents of sectarian killings in different parts of the country in the past couple of years, but Haripur district has generally remained peaceful.

A large contingent of police have been deployed in the area to prevent any reprisal killings after the shooting, police said.