(CNN) -- A Greyhound passenger bus turned over onto its roof early Saturday while traveling through southern Ohio, authorities said.
At least 34 people who were on board the bus were taken to hospitals, six of them by helicopter, said Butler County emergency management spokesman Jeff Galloway.
The bus was carrying 52 people when it overturned, he said.
A sheriff's office spokeswoman had previously said that the bus was carrying more than 80 people.
The bus originated in Cincinnati and was heading to Detroit.
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