An American editor of a Myanmar-based news outlet was detained by authorities in Yangon Monday while he was attempted to board a flight out of the coup-hit country, his employers said.

United States citizen and managing editor of Frontier Myanmar Danny Fenster was detained at Yangon International Airport in Myanmar the outlet said in a statement on its verified Twitter account.

The news agency said in a statement that “We don’t know why Danny was detained and haven’t been able to contact him since this morning. We are concerned for his wellbeing and call for his immediate release. Our priorities right now are to make sure he is safe and to provide him with whatever assistance he needs.”

In a message shared with a media outlet, Fenster’s brother Bryan said the family was “stunned and extremely confused” by the detention. “We’ve been assured that there is no concern for his safety but no doubt we are very worried,” he added.

According to the monitoring group reporting ASEAN, at least 34 journalists and photographers remain in custody across Myanmar.  Japanese reporter Yuki Kitazumi was detained in Myanmar in April and was also held in Insein until being freed earlier this month.