Myanmar's military has confirmed it has taken control of the country after Aung San Suu Kyi and other political leaders were arrested in the early hours.
The coup comes after tensions rose between the civilian government and the military following a disputed election.
Hours after the arrests, military television confirmed it was declaring a state of emergency for one year.
Myanmar, also known as Burma, was ruled by the military until democratic reforms began in 2011.
In November's election, Ms Suu Kyi's National League for Democracy (NLD) won enough seats to form a government. The army says the vote was fraudulent.
The newly-elected lower house of parliament was due to convene for the first time on Monday but the military was calling for a postponement.
The military said it was handing power to commander-in-chief Min Aung Hlaing.
Soldiers are on the streets of the capital, Naypyitaw, and the main city, Yangon.
Mobile internet data connections and some phone services have been disrupted in major cities, while the state broadcaster MRTV says it is having technical issues and is off air.
The BBC's South East Asia correspondent, Jonathan Head, says that under the constitution the military has significant powers to declare a state of emergency, but detaining political leaders like Ms Suu Kyi is a provocative and very risky move, one which may well be strongly opposed, our correspondent says.
NLD spokesman Myo Nyunt told the Reuters news agency by phone that Ms 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.
Soldiers also visited the homes of chief ministers in several regions and took them away, family members said.