About a dozen children were on the bus as seven passengers were saved and taken to a hospital, the interior ministry says.
At least 45 people have died in an overnight bus accident on a highway south of the Bulgarian capital.
The cause of Tuesday’s accident on a highway 40km (26 miles) from Sofia was yet to be determined.
“Forty-five or 46 people were killed,” Nikolay Nikolov, head of the Fire Safety and Civil Protection Department under the Ministry of Interior, told public broadcaster BNT.
“Seven passengers were saved” and taken to a hospital in the capital, he added.
According to the bTV channel, 12 children were on board the bus, which was going from Turkey’s main city of Istanbul to Skopje in North Macedonia.
Prime Minister Zoran Zaev, who reportedly wanted to visit the scene of the crash, said the victims were probably fellow Macedonians.
“We don’t know if all the victims are from North Macedonia, but we assume so because the bus is registered in the country,” he told Nova TV.
The state prosecutor’s office has launched an investigation.
At least 45 people killed in bus accident in Bulgaria – Aljazeera.com