BUDAPEST, Hungary (AP) — A passenger bus traveling on a highway in Hungary early Sunday went off the road and into a ditch where it overturned, killing 12 and injuring others, police said.

The bus, which was carrying a group of Polish tourists, was traveling on eastbound lanes near the town of Mezokeresztes when it overturned on the M3 motorway around 140 kilometers (87 miles) east of Hungary’s capital, Budapest, at around 1 a.m. on Sunday.

In a statement, police said it was likely that the driver fell asleep, causing the accident, and that the driver had been taken into custody.

Hungary’s National Directorate for Disaster Management said in a statement that 57 passengers and two drivers were traveling on the bus at the time of the accident, and that several of the passengers had been trapped under the vehicle when it overturned.

Polish Foreign Ministry spokesperson Maciej Wewiór told Polish news agency PAP on Sunday that all of the people on the bus were Polish citizens.

The bus was carrying people from Poland’s southeastern Podkarpackie region who were returning from a pilgrimage in Bosnia-Herzegovina, the regional government in Rzeszow, Poland, said in a Facebook post.

Hungarian Prime Minister Péter Magyar wrote in a statement on Facebook that at least 10 people were seriously injured in the crash. He offered his condolences to the families of the victims and thanked rescue workers who were dispatched to the scene.

Polish President Karol Nawrocki expressed his “deep sorrow” over the accident, writing in a post on X: “I join the families and loved ones of the victims in prayer and deep sympathy.”