An American editor of a Myanmar-based news outlet was detained by authorities in Yangon Monday as he 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, the outlet said in a statement on its verified Twitter account.
The US State Department said it was "aware of reports" of the arrest.
"We take seriously our responsibility to assist US citizens abroad, and are monitoring the situation," a spokesman said, while declining to provide further details for privacy reasons.
Myanmar has been in uproar since the military seized power in a February 1 coup, with near-daily protests and a nationwide civil disobedience movement.
More than 800 people have been killed by the military, according to a local monitoring group.
The press has been caught in the crackdown as the junta tries to tighten control over the flow of information, throttling internet access and revoking the licences of local media outlets.
"We do not know why Danny was detained and have not been able to contact him since this morning. We are concerned for his wellbeing and call for his immediate release," Frontier said in a tweet.
"Our priorities right now are to make sure he is safe and to provide him with whatever assistance he needs."
Fenster, 37, had been working for the outlet for around a year and was heading home to see his family, Frontier's chief editor Thomas Kean told AFP.
The outlet had learned at around 10 am that Fenster had not been allowed to board his flight from Yangon, he added.
In a message shared with AFP, 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 said.
At least 34 journalists and photographers remain in custody across Myanmar, according to monitoring group Reporting ASEAN.
- 'No one outside their grasp' -
Frontier said it understood Fenster had been transferred to Yangon's notorious Insein prison.
"With the arrest of a US citizen and a respected journalist, it is signalling a new normal," Herve Lemahieu, an expert on Myanmar at Australia's Lowy Institute, told AFP.
The junta "will hope this serves as a deterrent for local journalists. A sign that no one is outside their grasp".
Japanese reporter Yuki Kitazumi was detained by authorities in Myanmar in April and was also held in Insein until being freed earlier this month.
On his return to Tokyo he said Burmese political prisoners in the jail had told him they were tortured with beatings and sleep deprivation.
In March a BBC journalist was briefly detained after being seized by plainclothes officers while reporting outside a court in the capital Naypyidaw.
Separately, Polish photojournalist Robert Bociaga -- who was also arrested while covering protests -- was released in March after nearly two weeks in detention.
The arrest comes as civilian leader Aung San Suu Kyi voiced defiance Monday in her first court appearance since being detained in the coup, vowing her ousted political party would live on.
In the 2021 Reporters Without Borders Press Freedom Index, Myanmar ranked 140 out of 180 countries.
Since the coup, journalists in Myanmar "face systematic arrest campaigns and censorship", the watchdog said.
"Many will resign themselves to working clandestinely in order to be free to report what is happening and to evade the police," it added.