A car bomb exploded outside a KFC fast-food restaurant in the Pakistani city of Karachi yesterday, killing three people and wounding 15, police and doctors said.

Provincial authorities said they suspected Islamist militants and cast doubts on a claim of responsibility by a separatist group from nearby Baluchistan province which said it had targeted an office of a state-run Pakistani oil company.

Two other Karachi KFC restaurants, a Pakistani franchise of the US global food chain owned by YUM Brands Inc, have been attacked in recent months.

Some victims suffered severe burns in the bombing, which blew a metre-wide hole in the street and engulfed it in a fireball that gutted six or seven other parked cars in the centre of the southern city, Pakistan's commercial hub. A small Suzuki sedan blew up just before 9 a.m. (0400 GMT), gutting the ground-floor restaurant and shattering all the windows in the six-storey building.

The building houses several oil and gas exploration firms, including Pakistan Petroleum (PPL) which runs Pakistan's largest gas field in Baluchistan.

The restaurant was shut at the time, but the street, one of Karachi's busiest, was full of people arriving for work.