Myanmar leader Aung San Suu Kyi and other senior figures from the ruling party have been detained in an early morning raid, the spokesman for the governing National League for Democracy said on Monday.
The move came after days of escalating tension between the civilian government and the powerful military that stirred fears of a coup in the aftermath of an election the army says was fraudulent.
Spokesman Myo Nyunt told Reuters by phone that Suu Kyi, President Win Myint and other leaders had been "taken" in the early hours of the morning.
"I want to tell our people not to respond rashly and I want them to act according to the law," he said, adding he also expected to be detained.
Phone lines to Naypyitaw, the capital, were not reachable in the early hours of Monday.
A military spokesman did not answer phone calls seeking comment.
An NLD lawmaker, who asked not to be named for fear of retaliation, said another of those detained was Han Thar Myint, a member of the party's central executive committee.