The minibus carrying the migrants went off the road and rolled into a ditch in the province of Van on Thursday.
Footage from the scene showed the minibus in the ditch, with the casualties laid out on the side of a road.
Broadcaster NTV said some of the passengers had fallen off the bus as it rolled into the ditch.
The destination of the bus and the nationalities of the migrants were not immediately clear.
NTV quoted Van Governor Mehmet Emin Bilmez as saying the migrants were thought to be Afghan, Pakistani and Bangladeshi.
Numbers declined sharply in 2016 when Turkey, in exchange for 3 billion euros in EU aid and a promise to ease visa restrictions for Turks, began to exert more control on migrants trying to cross to Europe.
(This story has been recast from Reuters to highlight possibilities that some of the victims are from Bangladesh)