One man died after a train traveling from Sofia to Varna derailed near the central Bulgarian city of Stara Zagora on Saturday, 15:17 EEST (13:17 GMT).

The victim was the train's driver.

Fifteen were left injured, two of them in a critical condition, authorities say. Prime Minister Plamen Oresharski, however, said the number their number could rise.

He also wrote on his Facebook profile he was closely following the developments and had sent Transport Minister Danail Papazov and other officials to the station where the events took place.

Those wounded were taken to the nearest hospital, according to the Bulgarian National Radio, which quotes official sources.

Most of them were over 43 years of age, and no children were among the injured. It is yet unknown why four carriages and the engine went off the track, but the reasons are under investigation, the Interior Ministry's Chief Secretary Svetlozar Lavarov declared.

The locomotive of the train crossing the south of Bulgaria spinned while derailing and hit the carriages behind it.

Еarlier it was reported that the incident happened at the Kaloyanovets train station near Stara Zagora, where the composition had been divided, with some of the cars heading for the southern Black Sea city of Burgas.

Bulgarian State Railways (BDZ) chief executive Hristiyan Krastev reported the track had recently undergone repairs.