At least 45 people, including 12 children, have died after a bus crashed and caught fire in western Bulgaria, officials say.

The incident happened on a motorway at about 02:00 local time (00:00 GMT) near the village of Bosnek, south-west of the capital Sofia.

 

The bus was registered in North Macedonia and was carrying tourists returning from Turkey.

 

Seven people escaped from the bus and were taken to hospital with burns.

 

A Bulgarian interior ministry official said it was unclear if the bus had caught fire and then crashed or burst into flames after crashing.

 

Officials said the vehicle appeared to have hit a highway barrier and pictures showed a section of the road where the barrier had been shorn off.

Macedonian Foreign Minister Bujar Osmani told reporters the coach party had been returning to the capital Skopje from a weekend holiday trip to the Turkish city of Istanbul.

 

Macedonian Prime Minister Zoran Zaev spoke to one of the survivors, who told him that passengers were sleeping when the sound of an explosion woke them.

 

"He and the other six survivors broke the windows of the bus and managed to escape and save themselves," Mr Zaev told Bulgarian media.

 

Bulgaria's interim Prime Minister Stefan Yanev described the incident as "a huge tragedy".

 

"Let's hope we learn lessons from this tragic incident and we can prevent such incidents in the future," he told reporters as he visited the site of the crash.

 

The area around the site of Tuesday's incident on the Struma motorway has now been sealed off. Footage from the scene shows the charred vehicle, gutted by the fire.

 

After arriving at the scene, Bulgarian Interior Minister Boyko Rashkov said the victims had been completely burned, television station BTV reports.

 

Investigative service chief Borislav Sarafov said "human error by the driver or a technical malfunction are the two initial versions for the accident".