Twelve people have died after a bus carrying a group of Polish tourists overturned on the M3 motorway in Hungary on the way back from Bosnia and Herzegovina.

Local police said the bus crashed near the town of Mezőkeresztes after it “went off the straight road into a ditch and overturned” at 1am local time. Early reports suggested the driver had probably fallen asleep. He survived the crash and was taken into custody.

The bus was carrying a group of pilgrims from Poland’s south-eastern Podkarpackie region who were returning from a pilgrimage to the Catholic shrine in Međugorje, in southern Bosnia and Herzegovina, with 57 passengers and two drivers onboard.

Poland’s foreign ministry said “virtually all” passengers were transferred to local hospitals in Eger, Debrecen and Miskolc, and 10 people were in a serious condition. The Hungarian ambulance service said 37 people sustained minor injuries.

Polish and Hungarian leaders expressed their condolences after the crash. Poland’s president, Karol Nawrocki, said: “With deep sorrow, I received the tragic news of the accident involving a Polish bus in Hungary, in which so many of our compatriots perished.

“In the face of this unimaginable tragedy, which has touched us all, I join in prayer and profound compassion with the families and loved ones of the victims.”

Hungary’s prime minister, Péter Magyar, expressed his “sincere condolences to the families of the victims” and thanked the emergency services involved in the rescue operation.

Poland’s infrastructure minister, Dariusz Klimczak, said the general inspectorate of road transport would conduct enhanced checks on all buses and drivers’ working hours.

The owner of the bus company involved in the crash told Business Insider Polska that the vehicle “was driven by two experienced drivers”.

The investigation into the crash will be led by a group of Polish prosecutors from the south-eastern town of Krosno, the prosecutors’ office said in a statement.

Međugorje, despite some doubts about its religious history, is a popular summer destination for Polish Catholics.

In 2022, 12 people died and 30 were injured when a bus carrying Polish pilgrims to Međugorje crashed in Croatia. In 2002, 20 Polish pilgrims died and 31 were injured in a bus crash in Hungary.