Even as the North Korean government this month allowed two high-profile, U.S. Christian bands to perform at a music festival in Pyongyang, the fear of punishment authorities have instilled in North Korean Christians keeps most of them from publicly revealing their faith.

As many as 400,000 Christians are estimated to worship secretly in the country, and Suzanne Scholte, head of an association of some 60 groups campaigning for change in the country called the North Korean Freedom Coalition (NKFC), estimates that more than 200,000 North Koreans are held in political prison camps for various perceived “disloyalties” to the regime, including adherence to Christianity. [video]