A U.S. journalist detained in Myanmar was sentenced to 11 years in prison by a military court on Friday.

Danny Fenster was convicted on a three – count charge of breaching immigration law, unlawful association and incitement to sedition, his employer Frontier Myanmar said.

The 37-year-old faces further charge of terrorism and sedition that were added on Wednesday and could see him handed a life sentence, his lawyer says.

Those counts will be heard separately at an upcoming trial.

The military junta in Myanmar has been cracking down on critical voices since it took power in a coup in February.

Fenster has been detained for five and a half months and is a senior editor of the English-language Frontier Myanmar magazine.

He was arrested at Yangon airport May ending just before he was due to board a flight to the United States.

He has since been held at Insein Prison, which is notorious for its appalling conditions.

“Everyone at Frontier is disappointed and frustrated at this decision. We just want to see Danny released as soon as possible so he can go home to his family,’’ Frontier Myanmar’s chief executive Thomas Kean said.

Myanmar’s military ousted de facto leader Aung San Suu Kyi in the coup on Feb. 1, the 76-year-old is under house arrest and facing trial for various alleged offences.

The military junta is suppressing resistance with brutal force; more than 1,200 people have been killed, according to an estimate from prisoners’ aid organisation AAPP.

About 10,000 others have been arrested, including many journalists, and others have fled the country.

Foreign media representatives have long been considered relatively safe.