Four prisoners who are considered “extremely dangerous” escaped from a county jail in Ohio early Sunday morning after overpowering two guards, authorities said.

The inmates used a homemade weapon known as a shank and stole the keys to a corrections officer’s vehicle, which was used in the first part of their escape from Gallia County Jail, Sheriff Matt Champlin said at a news conference.

He said the inmates, all men, had help from at least one individual on the outside.

Authorities said that a second vehicle was waiting for the inmates about a block from the jail and was later found in an unspecified part of Pennsylvania.

Three of the escaped prisoners have been caught just under 600 km away in North Carolina after a day on the run, Associated Press said. One inmate remains at large.

A shopping centre near Pittsburgh was briefly closed because one of the escapees was believed to be in the area, Pennsylvania State Police said.

The sheriff said the two female jail officers who were on duty were not seriously injured during the escape, which happened around 12.15am.

The episode prompted a fresh round of criticism of the southern Ohio jail, after a fatal overdose from contraband and an inmate’s suicide in the past month.

During the news conference, the mother of a prisoner who died confronted the sheriff over the conditions at the jail.

“Some out there are calling for change and I could not agree with you more,” Mr Champlin said.

One of the fugitives, Brynn Martin, had previously escaped from the same jail, the sheriff said. Court records show he was charged this month with escape.

Public records show Martin has an extensive criminal record, and had been housed at a correctional facility in another county but was brought back to the jail for a court appearance.

“Bad men continue to try to fight to free themselves and terrorise our community,” Mr Champlin said.

Authorities identified the other escapees as Christopher Clemente, Troy McDaniel Jr nd Lawrence Lee.

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Previous charges against them included domestic violence, assault, menacing, drug possession, burglary and unlawful restraint, court records showed.

The sheriff said the 22-bed jail employs nine full-time corrections officers. It is housed in the basement of the county courthouse in Gallipolis, Ohio, which is about 100 miles southeast of Columbus.

He said his office has been constrained by the dormitory-type setup of the jail, which is at least 50 years old, as well as difficulty recruiting officers. He said their salaries are $11 (£9) to $15 (£12) an hour.

“We are very limited on the modifications we can make on our facility to secure these types of inmates,” Mr Champlin said. “I have and I will continue to search for solutions to this problem.”