Explosion rocks Pakistan's commercial capital

At least one person was killed and nearly a dozen injured in an explosion in Pakistan's commercial capital Karachi on Monday evening, police and health officials said.

The blast -- second in less than a week -- occurred in an apparel warehouse in the city's busiest southern business district, Sharjeel Kharl, a city police chief, told reporters.

TV images showed giant plumes of fire and thick smoke billowing upward from the warehouse as rescuers were shifting the injured to the ambulances.

A police van and several other vehicles were completely or partially damaged in the blast.

According to initial investigations, the bomb was planted in a motorbike parked outside the warehouse.

Investigators believe the police van could be the target of the blast.

No group has claimed responsibility for the blast.