KARACHI: At least six people died and three were injured when the roof of a cold storage factory in New Karachi's industrial zone collapsed on Monday.

A blast in factory's ammonia gas tank stirred a gas leakage, causing the roof of the factory to cave in.

The injured were shifted to Abbasi Shaheed Hospital for treatment, rescue sources said.

In the wake of the incident, the factory owner, Mr. Iqbal, suffered a cardiac arrest after which he was shifted to a local hospital for treatment.

Rescue and search operations for survivors are underway.