BUSAN (Yonhap) — Nine oriental medicine doctors and three medical students have been indicted on charges of promoting North Korean ideologies in breach of an anti-North Korea law, prosecutors said Tuesday.

The Busan District Prosecutors’ Office said they are suspected of publishing a number of books between 2010 and 2013 with pro-North content such as the North’s guiding philosophy “juche ideology.”

A 42-year-old doctor, whose identity was withheld, is also charged with possessing a total of 527 articles that are classified as benefiting the North, including the memoir of Kim Il-sung, Kim Jung-un’s grandfather and the nation’s founder.

They used websites or emails to exchange draft versions of the content they created to educate people on pro-North Korean ideologies, prosecutors said.

The defendants are also suspected of praising the leaders of the North, by holding a birthday party for them in 2012 and planning ceremonies for the death of leaders Kim Il-sung and Kim Jong-il, according to prosecutors.

The National Security Law prohibits South Korean citizens from contacting North Koreans without government approval and engaging in activities benefiting the North.