Bulgarian police have charged a religious leader and six others with supporting the Islamic State militant group.
Prosecutors said the charges against Muslim prayer leader Ahmed Mussa, five men and one woman include propagating an anti-democractic ideology and incitement to war.
Bulgarian security forces raided more than 40 homes and a mosque in southern Bulgaria on November 25 to seize books and computers in a special operation aimed at uncovering radical Islamist activities.
Police uncovered a large number of shirts and banners with the logo of the Islamic State.
Investigators also found evidence that the detainees helped western Europeans on their way to join the Islamic State group.
In March, Mussa was sentenced to a year in jail for spreading radical Islam, but was freed pending an appeal.
About 12 percent of Bulgaria's population of 7.3 million is Muslim.