At least 14 people were killed while several others were injured in a blast near the Sher shah Paracha Chowk, Karachi, Aaj News reported on Saturday.

The explosion took place around a drain located underneath a two-storey building that housed offices of a bank among others.

A second explosion also occurred at the site where rescue work was underway later. However, reports suggested there was no harm to life in the second explosion.

In a tweet, Murtaza Wahab, Karachi Administrator and Advisor to Sindh CM said that investigation is going on to ascertain the cause of the blast and necessary treatment is being provided to the injured.

Initial reports indicated the toll could be higher with video footage suggesting severe damage to the building and nearby vehicles.

The two-storey building can be seen severely damaged, and authorities fear people trapped under the debris.

The injured were shifted to Civil Hospital.

Pakistan Tehreek-e-Insaf's (PTI) leader and Member of the National Assembly Alamgir Khan's father was also among those killed, PTI's Karachi President Khurram Sher Zaman confirmed later.

Police suspect that accumulation of gases in the drain underneath the building caused the blast. A bomb disposal unit also arrived at the location of the blast.

Earlier, Police and Rangers officials cordoned off the area.

Meanwhile, Sindh Chief Minister Murad Ali Shah took notice of the blast and ordered an immediate inquiry. The CM also extended his condolences to the grieving families.

He also issued instructions to the secretary of health to provide necessary facilities to the injured at the Civil Hospital.

Sindh Minister for Information and Labour Saeed Ghani also visited the site and reviewed the rescue operation.

Closely monitoring situation: HBL

Meanwhile, HBL, in a statement, offered its sympathies to the bereaved families.

"An unfortunate incident, involving an explosion, took place at our branch in Sher Shah,Karachi, this afternoon, 18 December 2021," HBL said in a statement.

"Our sympathies are with the bereaved families."

The statement further said that the bank is closely monitoring the situation under the guidance of the authorities, adding that the cause and nature of the explosion is being determined

"As the details become available, we will provide them to the Media," the statement added.

"Currently, the focus of the Bank is to work closely with the authorities in facilitating all rescue and relief efforts and provide support to the families of the affected. Our main concern is the safety of our customers and our staff."