Officials say a multistory building has collapsed in Pakistan’s southern port city of Karachi, killing at least six people and injuring several others.

Rescuers were searching for trapped survivors after the incident in the impoverished Lyari neighbourhood of Karachi.

At least 13 people have died after a five-storey residential building collapsed in Karachi's Baghdadi area of Lyari. Rescue teams are working day and night to search for 25 to 30 people still trapped under the rubble.