Western leaders condemned the coup by Myanmar's military against Aung San Suu Kyi's democratically elected government and hundreds of thousands of her supporters took to the social media to voice their anger at the takeover.
The sudden turn of events in the early hours of Monday derailed years of efforts to establish democracy in the poverty-stricken country and raised more questions over the prospect of returning a million Rohingya refugees.
The UN Security Council will meet on Tuesday, diplomats said, amid calls for a strong response to the detention of Ms Suu Kyi and dozens of her political allies, although Myanmar's close ties with council member China will play into any decision.
US president Joe Biden said the coup was a direct assault on Myanmar's transition to democracy and the rule of law.
The army handed power to military chief Gen Min Aung Hlaing and imposed a state of emergency for a year in the country, saying it had responded to what it called election fraud.
Gen Min Aung Hlaing, who had been nearing retirement, promised a free and fair election and a handover of power to the winning party, without giving a timeframe.
Ms Suu Kyi’s National League for Democracy (NLD) party, which won a landslide 83 per cent in a November 8th election, said she called on people to protest against the military takeover, quoting comments it said were written earlier in anticipation of a coup.
But the streets were quiet overnight after troops and riot police took up positions in the capital, Naypyitaw, and the main commercial centre Yangon (formerly Rangoon). Phone and internet connections were disrupted.
Many in Myanmar (formerly Burma) voiced their anger on social media.
Data on Facebook showed more than 325,000 people had used the #SaveMyanmar hashtag denoting opposition to the coup, and some people changed profile pictures to black to show their sorrow or red in support of the NLD, often with a portrait of the 75-year-old Ms Suu Kyi, the 1991 Nobel Peace Prize winner.
“We as a citizen of Myanmar not agree with the current move and would like to request the world leaders. UN and the world medias help our country – our leaders – our people – from this bitter acts,” said one widely reposted message.
Four youth groups condemned the coup and pledged to “stand with the people” but did not announce specific action.
Ms Suu Kyi, President Win Myint and other NLD leaders were "taken" in the early hours of Monday morning, said NLD spokesman Myo Nyunt. UN human rights chief Michelle Bachelet said at least 45 people had been detained.
Consolidating the coup, the junta removed 24 ministers and named 11 replacements to oversee ministries including finance, defence, foreign affairs and interior.
Banks said they would reopen on Tuesday after suspending services on Monday amid a rush to withdraw cash. Yangon residents had also rushed to stock up on supplies.
Ms Suu Kyi’s election win followed about 15 years of house arrest between 1989 and 2010 and a long struggle against the military, which had seized power in a 1962 coup and stamped out all dissent for decades until her party came to power in 2015.
Her international standing as a human rights defender was severely damaged after she failed to stop the expulsion of hundreds of thousands of Rohingyas in 2017 and defended the military against accusations of genocide. But she remains hugely popular at home and is revered as the daughter of Myanmar’s independence hero, Aung San.
The coup followed days of tension between the civilian government and the military. In the pre-written statement on Facebook, Ms Suu Kyi was quoted as saying that an army takeover would put Myanmar “back under a dictatorship”.
“I urge people not to accept this, to respond and wholeheartedly to protest against the coup by the military,” it said. The authenticity of the statement was not independentlyt confirmed.
Supporters of the military celebrated the coup, parading through Yangon in pickup trucks and waving national flags. “Today is the day that people are happy,” one nationalist monk told a crowd in a video published on social media.
Democracy activists and NLD voters were horrified and angry. "Our country was a bird that was just learning to fly. Now the army broke our wings," student activist Si Thu Tun said.
Senior NLD leader Win Htein said in a Facebook post the army chief’s takeover demonstrated his ambition rather than concern for the country.
In the capital, security forces confined members of parliament to residential compounds on the day they had expected to take up their seats, representative Sai Lynn Myat said.
The United Nations led condemnation of the coup and calls for the release of detainees and restoration of democracy in comments largely echoed by Australia, Britain, the European Union, India, Japan and the United States.
In Washington, Mr Biden called on the international community to press Myanmar’s military to give up power, release detainees and refrain from violence against civilians. Those responsible for the coup would be held accountable, he said.
In Japan, a major aid donor with many businesses in Myanmar, a ruling party source said the government may have to rethink the strengthening of defence relations with the country undergone as part of regional efforts to counterbalance China.
China called on all sides in Myanmar to respect the constitution and uphold stability, but “noted” events in the country rather than expressly condemning them.
Bangladesh, which is sheltering around one million Rohingya who fled violence in Myanmar, called for "peace and stability" and said it hoped a process to repatriate the refugees could move forward. Rohingya refugees in Bangladesh also condemned the takeover.
The Association of Southeast Asian Nations, of which Myanmar is a member, called for "dialogue, reconciliation and the return to normalcy" while in Bangkok, police clashed with a group of pro-democracy demonstrators outside Myanmar's embassy.
"It's their internal affair," a Thai government official said – a hands-off approach also taken by Malaysia and the Philippines.
The November vote faced some criticism in the West for disenfranchising many Rohingya but the election commission rejected military complaints of fraud.
In its statement declaring the emergency, the military cited the failure of the commission to address complaints over voter lists, its refusal to postpone new parliamentary sessions, and protests by groups unhappy with the vote. – Reuters