More than 200 inmates escaped from a jail in the southern Pakistani city of Karachi late on Monday when they overpowered prison guards after being allowed to leave their cells following a series of earthquakes, local officials and police said.

The jailbreak began just before midnight and continued into the early hours of Tuesday after hundreds of prisoners were allowed into the courtyard of the District Malir prison because of the tremors, Zia-ul-Hasan Lanjar, the provincial law minister, told reporters at the scene on Tuesday.

Police said the prisoners snatched guns from prison staff and forced open the main gate after a shootout, evading paramilitary soldiers. At least one prisoner was killed and three guards wounded, said Provincial Police Chief Ghulam Nabi Memon.

"I heard the firing for quite some time and then some time later prisoners made their way out running in all directions," Bukhsh, a private security guard at a residential complex opposite the jail who goes by a single name, told Reuters.

He added that some of the prisoners entered the apartment complex before being taken away by police.

On Tuesday, a Reuters reporter who visited the prison saw shattered glass and damaged electronic equipment. A meeting room, for prisoners to see their families, had been ransacked. Anxious family members had gathered outside.

The jailbreak was one of the largest ever in Pakistan, Lanjar said. The prison, which houses 6,000 inmates, is in the Malir district of Karachi, Pakistan's biggest city.

Prisoners ran through the area throughout the night, some of them barefoot, with police giving chase, local TV footage showed. About 80 of those who escaped had been caught, said Murad Ali Shah, the provincial chief minister.

The jail's superintendent, Arshad Shah, told reporters that there were 28 prison guards on duty at night, and that "only a few of such a large number of prisoners escaped". He said the prison did not have security cameras.

Officials said the inmates, many of them heroin users, had been unnerved by the earthquakes.

"There was panic here because of earthquake tremors," said Lanjar.

The provincial chief minister said it was a mistake for prison authorities to have allowed the prisoners to leave their cells. He urged the inmates still at large to hand themselves in, or face a serious charge for breaking out.

"Petty crime charges will become a big case like terrorism," Shah said.