More than 200 prisoners escaped from a jail in Pakistan's largest city following an earthquake in the early hours of Tuesday, police said.

Thousands of inmates broke down doors and the locks of their cells and shattered windows after they felt tremors shake the walls at Malir Jail in Karachi.

Of those who escaped the prison, police said 80 inmates had been recaptured and searches were ongoing for more than 130 still at large. One prisoner was killed in the operation and two prison officers injured.

A prison superintendent told the BBC inmates began shouting from their cells and barracks around midnight as they were terrified the building would collapse on top of them.

After the frenzy turned violent, police said they responded with warning shots, firing guns into the air.

While many returned to their cells, others stormed the main gate in panic - with 216 inmates using the opportunity to escape the prison altogether.

Police are now going door-to-door, visiting past residences to arrest those who are still on the run.

The facility in the Malir district is Sindh province's second largest prison, and is over capacity. While it can accommodate up to 2,200 prisoners, there are at least 5,000 inmates there currently.

The minister for prisons in the province, Ali Hassan Zardari, has ordered an investigation and warned any officers at fault will be disciplined.

The prison's superintendent told the BBC the incident is "not a security lapse, it's all due to a natural disaster".

He said security teams at the prison were on high alert, and responded to the incident throughout.

Families have been protesting outside the jail's main gates, and police said relatives of other inmates are frustrated that visits have been postponed.