Eleven Media's executive editors Kyaw Zaw Lin and Nayi Min, and chief reporter Phyo Wai Win handed themselves over to police after the Yangon Regional Government accused them of causing "fear or alarm to the public" for a story that published "incorrect information" according to news reports.
A court ordered the journalists to remain in custody and they were taken to Insein prison, according to CPJ.
Separately, Myanmar State Counsellor Aung San Suu Kyi, the de facto leader of the civilian government, stated in an interview that "there is a lot of press freedom in Myanmar."
Despite high hopes for a more open press freedom environment as Myanmar began its transition to democracy under Suu Kyi, CPJ has documented how it has instead backtracked.
Last month, Reuters journalists Wa Lone and Kyaw Soe Oo were convicted under the Official Secrets Act and sentenced to seven years each in prison.