Blast hits Karachi petrol station

An explosion at a Shell petrol station in the southern Pakistani city of Karachi has injured at least 14 people, some seriously, police say.

Early reports that two people had died in the blast in the south of the city have not been confirmed, the authorities say.

Many of the injured have severe burns after an underground petrol storage tank went up in flames.

Police are investigating the blast but say they think it was an accident.

"It is not a bomb explosion," deputy inspector-general of police Tariq Jameel told Reuters news agency.

He said compressed natural gas (CNG), which many Pakistanis use in their cars, was probably the cause of the blast in the Defence Colony neighbourhood.

The station's roof collapsed and buried a number of people. Several cars were also damaged.

May bombings

In May, there was a string of minor bomb blasts at more than a dozen Shell petrol stations in Karachi.

No one was injured and no group admitted carrying out the attacks.

The Royal-Dutch Shell Group is an Anglo-Dutch firm that has a US subsidiary.

"Immediate measures have been taken to ensure safety and security at all Shell Pakistan facilities throughout the country," the company said in a statement.