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 south-west of the capital Sofia at about 02:00 local time (00:00 GMT).
The bus was registered in North Macedonia and was mainly carrying tourists from the country, who were 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 bus appeared to have hit a highway barrier and pictures showed a section of the road where the barrier had been shorn off. No other vehicles were involved in the accident.
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.
Bulgarian media reports say the vehicle, which had been travelling as part of a convoy of buses, had stopped off at a petrol station near Sofia about an hour before the accident.
The victims have not yet been named, but officials said they included children and young people, aged between 20 and 30.
Macedonian Prime Minister Zoran Zaev told Bulgarian television that most of the passengers on the bus were Macedonian, but one Belgian and one Serbian citizen were among them.
Mr Zaev said he 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 “an enormous 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”.