Bulgaria's State Agency for National Security, DANS, and the Interior Ministry are conducting Friday a joint special operation against suspected fraud in the energy sector.

The operation is taking place in the capital Sofia, the western city of Pernik, and the Danube towns of Kozloduy and Belene.

Kozloduy is the site of Bulgaria's only Nuclear Power Plant, NPP, while there is a debated project to build a second, Russian-sponsored one in Belene.

The operation comes on the heels of Sofia City Prosecutor's Office launching on August 9 a pre-trial procedure for large-scale embezzlement. The main lead in the investigation are payments from the National Electric Company, NEK, for consulting services for the Belene NPP project, made after the previous government of the Citizens for European Development of Bulgaria party, GERB, decided to freeze it in March 2012.

The operation was launched simultaneously in the above locations at 8:30 am Friday. A total of 17 facilities are being raided.

The prosecution stated they will not reveal any further details in order to not hinder the probe.