Updated

Prisoners were being treated under guard at a hospital after a private prisoner van crashed in southern Mississippi, killing the driver and injuring several others.

The van was carrying three guards and nine inmates when it drove off an interstate Sunday, hitting an embankment and trees before flipping over, police said. One guard and two prisoners were in critical condition late Sunday.

The van was carrying prisoners from Texas and Louisiana to different detention centers located along the East coast. All 12 occupants had to be cut from the crumpled wreckage of the white van, which lay on its roof with its windows shattered amid broken trees.

"The vehicle left the roadway on the right shoulder, collided with a raised embankment and slid and hit a couple trees before landing on its roof," Hattiesburg police spokesman Synarus Green told The Associated Press.

The van's driver, a 50-year-old security officer for a private prisoner transport agency, was pronounced dead at the scene of the single-vehicle crash off Interstate 59 in the Hattiesburg area, police said.

Green said another security guard and six other prisoners remained hospitalized with various injuries. Another prisoner was treated and released Sunday and was being held at a regional jail in Forrest County, he added.

Hattiesburg police officers were helping guard the prisoners at the hospital, Green said.

"We will make arrangements to get them back to where they came or the locations they were headed to," he said.

The van was operated by a company called Prisoner Transport Services, police said.

"Most of the prisoners were either from Louisiana or Texas and going to some portion of the United States," Green said, adding injured prisoners reported they were asleep when the crash occurred around 7 a.m. Sunday.

Green had no further details on where the prisoners came from, nor their identities and where they were headed. He said no foul play was suspected and the van was the only vehicle involved in the crash.

He said the van landed amid broken trees, complicating rescue crews' work.

"The front nose of the van is kind of short. So when it crushed back it kind of pinned both doors and so both of the front passengers had to be cut out. And they cut off the front end of the vehicle so where the prisoners were it's all closed off with the mesh gates over the windows so those they had to be cut out as well," Green said.

Green said authorities were not releasing further information about the driver until relatives have been notified. Other occupants also were not identified.