At least 45 people have been killed, including children, after a bus caught fire on a highway in western Bulgaria early on Tuesday, officials have said. The incident occurred on the Struma highway about 45 kilometers (28 miles) west of Sofia, near the village of Bosnek, at around 2 a.m. local time, as per local reports. While the cause of the accident is currently unclear, the bus, which reportedly has a Macedonian registration and was mostly carrying North Macedonian tourists, appeared to have hit a highway barrier either before or after it caught fire, Bulgarian officials said. Bulgarian investigative service chief Borislav Sarafov said, “Human mistake by the driver or a technical malfunction are the two initial versions for the accident.” Television footage showed the bus charred and gutted by fire in the middle of the highway, which was wet from rain. “On the 31st kilometer of the highway, there was an …