Violent mobs protesting the killing of two activists of a Sunni group took to the streets and torched vehicles in Pakistan's port city of Karachi on Thursday.

On Wednesday night, unidentified gunmen, riding a motorcycle, had shot dead two Sunni Tehrik activists and injured another on M A Jinnah Road.

Protestors torched two buses and a coach and there were reports of firing in some parts. Shopkeepers were forced to draw shutters in some areas.

Tension gripped parts of the city after exchange of fire in Ranchor Line locality. Para-military rangers and police were deployed in the wake of tension.

Reports say that the office of Sunni Tehrik was also attacked and burnt on Thursday morning.

The violence is seen as a turf war between ST and Muthahida Quami Movement, which is currently in power in Sindh province.

On Tuesday, the MQM claimed that four of its workers were injured in firing by the ST.