Twelve people were killed and dozens more injured when a Polish tourist bus veered off a Hungarian motorway and into a ditch, BBC reported. 

Police said the bus overturned after coming off the M3 motorway, which connects Hungary's capital Budapest with the north-eastern city of Nyregyhaza at around 01:00 local time on Sunday (23:00 GMT on Saturday).

Officers believe the driver fell asleep at the wheel. He has been taken into custody, according to BBC. 

Thirty-five out of the 57 passengers and two drivers onboard have been rescued by firefighters so far, state media reports.