SOFIA, Bulgaria — A bus carrying people home to North Macedonia from a tourist trip to Istanbul crashed and caught fire in western Bulgaria early Tuesday, killing at least 45 people, authorities and local media said.

The accident happened around 2 a.m. and there were children among the victims, authorities said. Seven people were taken to hospitals for treatment.

The cause of the crash was not immediately confirmed, but it appeared that the bus hit a highway guard rail, crashed and caught fire.

The bus was one of four traveling together. Officials said an investigation will be launched.

Photos taken shortly after the crash showed the bus engulfed in flames with plumes of thick, black smoke rising from the scene.

Interior Minister Boyko Rashkov told reporters at the crash site that he had “never in my life seen something more horrifying.”

“The picture is horrifying, the people who were on the bus are turned to charcoal,” Rashkov said. “It is impossible to say how many they were. There were four buses that traveled together, and it is possible that passengers changed buses during the stops.”

Media in North Macedonia reported that police were outside the Skopje offices of a travel company that is believed to have organized the trip to Turkey.

Bulgarian Caretaker Prime Minister Stefan Yanev, who also visited the site of the crash, told reporters it was

“a huge tragedy.”

“I take this opportunity to send my condolences to the relatives of the victims,” Yanev said. “Let’s hope we learn lessons from this tragic incident and we can prevent such incidents in the future.” (AP)