At least four people were killed and 22 more were injured after a passenger bus carrying teachers and their families on a weekend trip to Georgia overturned in Turkey's northeastern Ardahan province, Daily Sabah reported.

The accident occurred around 4 a.m on the Çıldır-Aktaş highway after the driver lost control of the vehicle while driving through the mountainous region. The driver and three passengers were killed, and five others were critically injured. All the injured people were hospitalized.

The local gendarmerie has opened an investigation into the cause of the accident.