Myanmar Coup: What is happening and why?
The army in Myanmar has seized control following a general election which Ms Suu Kyi's National League for Democracy (NLD) party won by a landslide.
The army had backed the opposition, who were demanding a rerun of the vote, claiming widespread fraud.
The election commission said there was no evidence to support these claims.
The coup was staged as a new session of parliament was set to open.
Ms Suu Kyi is thought to be under house arrest. Several charges have been filed against her. Many other NLD officials have also been detained.
Aung San Suu Kyi became world-famous in the 1990s for campaigning to restore democracy. She spent nearly 15 years in detention between 1989 to 2010 after organising rallies calling for democratic reform and free elections. She was awarded the Nobel Peace Prize while under house arrest in 1991.
In 2015, she led the NLD to victory in Myanmar's first openly contested election in 25 years.
Ms Suu Kyi has urged her supporters to "protest against the coup", but the streets of Myanmar are quiet. An NLD politician told the associated press(AP) news agency that the party was not planning protests, but working to "settle the problem peacefully".
People have been encouraged to show their opposition through acts of "civil disobedience".
Amid a night-time curfew, many people in Yangon banged pots and pans and honked their car horns in protest. Staff at dozens of hospitals and medical centres have walked out, and many others are wearing ribbons showing they oppose the coup. Some social media users have changed their profile pictures to one of just the colour red.
The commander-in-chief Min Aung Hlaing is now in charge. He has long wielded significant political influence, successfully maintaining the power of the Tatmadaw - Myanmar's military - even as the country transitioned towards democracy.
He has received international condemnation and sanctions for his alleged role in the military's attacks on ethnic minorities - the Rohinya genocide - forcing 700000 Rohinya muslims to flee to neighbouring Bangladesh in 2017.