Image copyright Tennessee Bureau of Investigations Image caption A Tennessee Bureau of Investigations agent photographed the suspects after their capture

Two US inmates who were on the run since Tuesday after shooting dead two prison officers have been captured, officials say.

Donnie Rowe and Ricky Dubose were seized in the state of Tennessee.

The men overpowered the guards as they were transported by bus to another facility in the state of Georgia.

This triggered a massive nationwide manhunt, with the authorities warning that the public was in "grave danger" because the inmates were armed.

On Thursday, officials said the two men were in custody following a car chase in rush hour traffic through Rutherford County, Tennessee.

Earlier that day, the two men had stormed into an elderly couple's home, put guns to their heads and tied them up with a belt, authorities say.

Dubose and Rowe remained inside the home of the couple - who police say are "extremely traumatised" - for three hours as they took clothing and jewellery, and ate beef stew.

After the convicts left in the couple's black Jeep Cherokee car, the man and woman managed to escape and call police.

Image copyright CBS Image caption Ricky Dubose (left) and Donnie Rowe were captured after a high-speed car chase

Rutherford County Sheriff's Office deputies spotted the black Jeep at around 18:00 local time about 50 miles (80km) southeast of Nashville and followed, leading to a car chase reaching speeds of over 100mph.

The suspects shot at police during the chase, but deputies did not return gunfire, Rutherford County Sheriff Michael Fitzhugh told reporters on Thursday night.

After Dubose and Rowe crashed their car, they ran towards another house and tried to steal the car in the driveway.

But an armed homeowner held the two at gunpoint with the help of a neighbour before police could arrive.

On Tuesday, police said Rowe and Dubose, who were both serving time at Baldwin State Prison for armed robbery, had taken control of a prison transport bus on Highway 16 - between the towns of Sparta and Eatonton.

"They were inside the caged area of the bus," Sheriff Sills said at a press conference. "How they got through the locks and things up to that area I do not know."

The prisoners "overpowered" the guards and "they then disarmed them and one of the subjects shot and killed both guards", according to a bulletin issued by the Putnam County Sheriff's office.

Sheriff Sills on Thursday night said he was "elated" by the capture of the "vicious hoodlums".

The authorities described the fugitives as "dangerous beyond description".

Correctional officers Christopher Monica, 42 and Curtis Billue, 58, were both killed, the Georgia Department of Corrections confirmed.

Georgia Governor Nathan Deal ordered flags at the state capitol to fly at half-mast on the day of their interments.

"Rest assured, justice will be served," Mr Deal said in a statement thanking law enforcement.

"The pain endured by the families and loved ones of Sergeant Christopher Monica and Sergeant Curtis Billue endures, however.

"We will do everything in our power to support their loved ones, and we will not forget their sacrifice and service."