Khar: A vehicle carrying explosives blew up in northwestern Pakistan on Wednesday killing six Taliban militants, a militant and officials said.

A hand grenade accidentally detonated setting off the ammunition and explosives in the vehicle, killing the six militants and injuring two others, a militant said.

The vehicle was travelling through the Bajaur region. Some residents thought the explosion was cause by a US drone missile attack.

But officials confirmed the blast was the result of the accidental detonation of ammunition.