Two Myanmar journalists working for Reuters news agency covering the country's ongoing Rohingya crisis and two security officers who helped them have been detained, the government said Wednesday.

The two male journalists, Thet Oo Maung Maung, who is also known as Wa Lone, and Kyaw Soe Oo, also known as Moe Aung, were detained by police around midnight Tuesday on the outskirts of Yangon, an Information Ministry report said.

They were then charged under the colonial-era Official Secrets Act of 1923 for obtaining "important documents concerned with security forces" in the Rakhine State in the country's west and other related information, it said.

Police Lt. Moe Yan Naing and Police Sergeant Khin Maung Lin, who were involved in the case, were also being charged under the same law, as well as under other police rules, the report said.

The United Nations and the international community have been accusing Myanmar of human rights violations allegedly committed by the country's security forces against Rohingya Muslims in Rakhine, causing more than 620,000 of them to flee to neighboring Bangladesh in recent months.

The U.S. Embassy in Yangon said in a statement that it is "deeply concerned by the highly irregular arrests of two Reuters reporters after they were invited to meet with police officials in Yangon last night."

"For a democracy to succeed, journalists need to be able to do their jobs freely," it said. "We urge the government to explain these arrests and allow immediate access to the journalists."