Former US President Bill Clinton on Monday called for the immediate release of two Reuters journalists being held in Myanmar.

“A free press is critical to a free society – the detention of journalists anywhere is unacceptable. The Reuters journalists being held in Myanmar should be released immediately,” Clinton said in a Twitter post.

Myanmar has accused Reuters reporters Wa Lone, 31, and Kyaw Soe Oo, 27, of breaching the country’s Official Secrets Act, a little-used law from colonial rule.

They are due to appear in court in the main city of Yangon on Wednesday. It will be their second appearance in court and the prosecutor could request that charges are filed against them.