A bus carrying 16 state prison inmates overturned on the New York State Thruway on Weds., Jan. 4, 2012. View Full Caption Flickr/cdogstar

MANHATTAN — A city Department of Correction bus transporting inmates from Rikers Island to an upstate prison overturned on the New York State Thruway Wednesday, sending all 16 inmates to the hospital, officials said.

The bus, which also had three city DOC employees on board, overturned on Interstate 87 in Ramapo, N.Y. en route to a prison in Ulster County about two hours outside the city, a DOC spokeswoman said.

No serious injuries were reported, and inmates and staff were taken to Good Samaritan Hospital in Suffern, N.Y., for medical attention, the DOC noted.

Names of the inmates involved in the incident were not being released by the department late Wednesday morning. The identity of the driver was also not released.

The agency said the cause of the incident is still under investigation. The inmates were treated and released from the hospital and returned to state custody by Wednesday evening, authorities said.

Staff from the New York State Department of Corrections — which oversees the prison system — were on site at the hospital for security, state DOC spokesperson Linda Foglia said.

The inmates are medium-security classified offenders, who were sentenced on crimes including grand larceny, robbery, possession of stolen property and attempted burglary, according to city Correction spokeswoman Sharman Stein.

The bus was carrying inmates from Rikers back to the correctional facility after they each had court appearances in the city, Stein said.