At least 10 people were killed and 11 others injured in a powerful explosion on Saturday at a bank branch constructed atop a sewage drain in the southern Pakistani city of Karachi's industrial area, police said.
The cause of the blast, at a branch of Pakistan's largest bank, Habib Bank Limited, could be a gas leak, a senior police officer said.
"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.
A petrol station located next to the bank in the Sindh Industrial Trading Estate, and cars parked nearby, were badly damaged.
Television footage showed the bank’s floor ripped apart, exposing twisted iron bars.
Another senior police officer, Sharjeel Kharal, told reporters it was not immediately clear how many were dead or injured in the explosion as the bank had a skeleton staff on Saturday.
Construction laws are often flouted in Pakistan. Several sewage drains have been concreted over in Karachi to make way for parking lots.
Last month, the country’s Supreme Court ordered the demolition of a multi-story apartment building found to have been constructed on an illegal plot at Karachi’s main thoroughfare.