SOFIA, BULGARIA — A bus has slammed into a highway barrier in Bulgaria, killing at least 45 people onboard, including 12 children, according to the BBC.


The bus had been part of a convoy of four, making a return trip from Istanbul to Skopje in North Macedonia.


However, the other busses were a few minutes ahead by the time of the accident, the cause of which remains unknown.


The New York Times reports one local mayor of a town close to the site saying that, ‘accidents are common in the area because of the steep gradient of the roads,’ while the BBC cites one of the investigators as saying ‘human error by the driver or a technical malfunction’ are currently the two most likely explanations.