KARACHI, Pakistan (Reuters] – An explosion at a Karachi bank branch that is located on a sewage line in Karachi’s industrial zone left 11 people dead and eleven others seriously injured.

Senior police officers said that the gas leak could have been the cause of this explosion at Habib Bank Limited’s branch in Pakistan.

“Our explosives teams are at work trying to ascertain the nature of the blast, but apparently the structure was constructed on drain and gas could be a probable cause,” Sarfaraz Nawaz told reporters.

The petrol station and nearby cars were severely damaged at the Sindh Industrial Trading Estate.

Television footage showed the bank’s floor ripped apart, exposing twisted iron bars.

Sharjeel Kharal (another senior officer in police) told reporters that it wasn’t immediately known how many people were killed or injured by the explosion. The bank was also equipped with a skeleton staff.

Pakistani construction laws often get ignored. Many sewage drains in Karachi have been reconstructed to create parking areas.

Last month, the country’s Supreme Court ordered the demolition of a multi-storey apartment building found to have been constructed on an illegal plot at Karachi’s main thoroughfare.