By Noreen O'Donnell
(Reuters) - A Greyhound bus flipped over and landed on its side in an Ohio cornfield early on Saturday, injuring more than 30 people, some seriously, authorities said.
The bus was traveling on Interstate 75, when the crash occurred at 3:48 a.m. local time in Liberty Township, about 25 miles north of Cincinnati, said Jeff Galloway, director of the Butler County, Ohio, Emergency Management Agency.
There were 51 passengers plus the driver on board the bus, which was en route from Cincinnati to Detroit, Michigan.
Of the injured, 28 were put into ambulances and six were airlifted to hospitals, Galloway said. None of the injuries appeared to be life-threatening, according to a statement from the Ohio State Highway Patrol.
As of mid-day Saturday, 16 people had been treated and released, said Alexandra Pedrini, a spokeswoman for Greyhound.
Several people were trapped in the bus and had to be extricated by rescue workers, according to the Highway Patrol.
The Highway Patrol is investigating the cause of the crash, which authorities said occurred when the bus drove off the right side of the highway, striking a tree and chain link fence, then overturning and sliding to a stop in a corn field.
Galloway said there were no signs that the bus was speeding. "No indication of anything," he said. "That's all under investigation."
The driver, who has worked for Greyhound for 15 years and was among the injured, had been on duty for about an hour before the accident, Pedrini said. She said she could not release the driver's name nor say whether he or she had been involved in any previous accidents.
The bus had passed a federal Department of Transportation-mandated inspection 14 days ago, she said.
"That's something they do every 12,000 miles," she said. "Everything passed. Everything was all good to go. All of the other inspections that the bus had to go through were up to date as well."
(Reporting by Noreen O'Donnell; Editing by Ellen Wulfhorst, Gunna Dickson and Vicki Allen)