Bulgaria's Prosecutor's Office and the National Security Agency (DANS) are conducting a special operation against radical ideologies in four Bulgarian cities, said the prosecution on its website.

The operation is part of an investigation for “propagation of fascist or other anti-democratic ideology or forceful change of the public and state order, provided in the Constitution” and “propagation of war”. Both violations, according to Bulgaria's Penal Code, are punishable by imprisonment or a fine.

Since the morning of November 25, gendarmerie and DANS officers searched 40 premises in Pazardzhik, Plovdiv, Smolyan and Haskovo and seized “multiple evidence”, the statement says.

“Additional information will be given when it does not jeopardise the operation,” the statement said.

According to unofficial information of the Bulgarian-language media, the operation is against supporters of the Islamic State (IS) terrorist organisation in Bulgaria.

As reported earlier on Tuesday, gendarmerie, police and DANS officers raided the Iztok Roma quarter in Pazardzhik, blocked and searched the mosque there and took away in a police car the local imam Ahmed Musa Ahmed, who has a jail sentence for propagating anti-democratic ideology.