SOFIA (Reuters) - At least 46 people, most of them tourists from North Macedonia, died as a bus crashed in flames on a highway in western Bulgaria on Tuesday, officials said.

       Children were among the victims, and seven survivors needing treatment for burns were rushed to hospital in the capital Sofia, Bulgarian interior ministry senior official Nikolai Nikolov told private BTV television.

       "At least 45 people were killed after a bus caught fire and crashed, or crashed and then caught fire," Nikolov said. His ministry later updated the toll to 46. There had been 53 people on board.

       The accident happened on Struma highway about 45 km (28 miles) west of Sofia around 2:00 a.m. (0000 GMT). The site had been sealed off and Bulgarian interim Prime Minister Stefan Yanev rushed to the scene of the tragedy.

       An official from Sofia emergency hospital said the seven people receiving treatment has jumped out of the burning bus. All were in stable conditions.

       North Macedonian Foreign Minister Bujar Osmani said the coach party was returning to Skopje from a weekend holiday trip to Istanbul, Turkey.

       (This story corrects nationality of victims in headline.)

       (Reporting by Tsvetelia Tsolova; Writing by Stephen Coates; Editing by Simon Cameron-Moore)