Reuters news agency said it was "outraged" by the arrest of two of its journalists in Myanmar Wednesday and accused authorities of an attack on press freedoms, as the US voiced concern over the detentions.
Myanmar reporters Wa Lone, 31, and Kyaw Soe Oo, 27, were held under the Official Secrets Act, the government announced, accusing them of having documents relating to unrest in Rakhine State, where a military crackdown has sent more than 620,000 Rohingya Muslims fleeing into neighbouring Bangladesh.
The United States Embassy in Myanmar said it was "deeply concerned" about the arrests and urged the government to allow access to the pair.
"For a democracy to succeed, journalists need to be able to do their jobs freely," it said in a statement.
Authorities released a staged image of the two journalists wearing handcuffs with documents displayed before them.
"We are outraged by this blatant attack on press freedom," said Reuters President and Editor-In-Chief Stephen J. Adler, in a statement posted on the company's website.
"We call for authorities to release them immediately."
The pair stand accused of intending "to send important security documents regarding security forces in Rakhine State to foreign agencies abroad," a statement released by the information ministry said.
They have been charged under a section of the Official Secrets Act that carries a maximum sentence of 14 years in prison.
- Media freedom fears -
The arrests come as Myanmar faces international opprobrium over the army crackdown in Rakhine, as refugees tell of horrifying attacks, murder, rape and arson.
The UN has said the army campaign, which saw hundreds of Rohingya villages razed to the ground, likely amounts to ethnic cleansing and has possible "elements of genocide" -- charges Myanmar vehemently denies.
Authorities have banned journalists from independently travelling to northern Rakhine, the epicentre of the unrest, which has been left virtually abandoned and scarred with torched villages.
The government statement said that action will also be taken against two policemen who had recently returned from duty in northern Rakhine. 
Since Nobel laureate Aung San Suu Kyi came to power in 2016 after decades of military rule, rights groups have expressed alarm over worsening freedom of expression.
The number of online defamation cases has shot up compared to the previous military-backed administration with a notorious telecommunications law ensnaring online satirists, activists and journalists.
A report by Free Expression Myanmar on Monday said that every case that has made it to court so far has ended with a guilty verdict and a prison sentence.
In one prominent case, Myanmar Now news agency editor Swe Win was charged with insulting a Buddhist monk who praised the killer of a Muslim government lawyer. The trial is still ongoing.
In October, a Burmese journalist, two reporters from Malaysia and Singapore and their driver were arrested in the capital Naypyidaw for flying a drone over parliament and sentenced to two months in prison while awaiting additional charges.
Independent reporting was almost completely snuffed out during Myanmar's half century under the junta, which operated one of the world's most draconian pre-publication censorship regimes.
© AFP