PAKISTAN – A gas cylinder explosion in Karachi, Pakistan, late Wednesday killed at least 16 people and left dozens others injured, according to authorities on Thursday.

The explosion occurred inside a three-story residential building in the densely populated Soldier Bazaar area of the city’s old quarter. The blast brought the structure down, trapping residents beneath the rubble.

Among the dead were women and children, authorities said.

At least 13 bodies and 18 injured people were transported to Civil Hospital Karachi, the city’s largest public health facility. Dr. Mohammad Sabir Memon, head of the hospital’s trauma center, told local daily Dawn that rescue efforts continued through the night.

Footage released by emergency responders showed workers combing through debris with their bare hands as distraught residents gathered nearby.

Building and roof collapses are frequent across Pakistan, largely attributed to lax safety standards and the widespread use of substandard construction materials.

Home to more than 20 million people, Karachi is particularly plagued by unsafe construction practices, illegal extensions, aging infrastructure, overcrowding and weak enforcement of building regulations.

The metropolis has witnessed several major disasters in recent years, including the Gul Plaza inferno last month that killed more than 70 people.