Military ruler General Min Aung Hlaing was moving quickly to consolidate his hold on power following the overthrow of elected leader Aung San Suu Kyi and the detention of her and allied politicians on Monday.
He told a business group on Wednesday night he could keep power for six months after a one-year state of emergency ends in order to hold fair elections.
But in a show of defiance to the generals, about a dozen of the lawmakers elected in a Nov. 8 ballot convened a symbolic parliamentary session in the quarters where they have been staying since the takeover.
Small protests took place in the main city Yangon and elsewhere, with activists saying three people had been arrested, and doctors were also mounting a campaign of civil disobedience.
But in a country with a bloody history of crackdowns on demonstrations, there was no mass outpouring of opposition to the coup on the streets.
The army seized power on Monday alleging irregularities in the election, derailing Myanmar's long and difficult transition to democracy. The move was condemned by the United Nations and Western governments, who called on the junta to respect Suu Kyi's National League for Democracy's landslide victory.
Opposition to the junta has emerged very strongly on Facebook, the country's main internet platform and underpins communications for business and government.
The Ministry of Communications and Information said Facebook - used by half of Myanmar's more than 53 million people - would be blocked until this Sunday, Feb. 7, because users were "spreading fake news and misinformation and causing misunderstanding." Facebook's WhatsApp messaging was also blocked.
Demand for VPN services to evade the blockade surged 4,300%, said Simon Migliano, Head of Research at Top10VPN.com. The government announced it would block VPN servers too.
Facebook was still available sporadically and demonstrators in the second city of Mandalay used it to livestream the first such street protest since the coup.
"People's protest against military coup," read one banner.
The group of around 20 people chanted: "Our arrested leaders, release now, release now."
Three people were arrested after the protest, student groups said. Reuters was unable to contact police for comment.
A dozen or so people also staged a protest in the main city of Yangon later before dispersing quickly.
Staff at government hospitals stopped work on Wednesday or wore ribbons in the NLD's red color. In response, the army announced on Thursday that people could get treatment in military hospitals.
Pictures shared on Wednesday showed workers at the agriculture ministry joining the campaign of disobedience too.
Other signs of anger have emerged. For two nights, people in Yangon and other cities have banged on pots and pans and honked car horns, with images circulating widely on Facebook.
"Lights are shining in the dark," said Min Ko Naing, a veteran of past campaigns against military rule, in a call to action. "We need to show how many people are against this unfair coup."
Suu Kyi, 75, has not been seen since her arrest along with other party leaders. Police have filed charges against her of illegally importing and using six walkie-talkie radios found at her home and she has been detained until Feb. 15.
The daughter of the former British colony's independence hero Aung San and the longtime leader of its democracy movement, Suu Kyi spent about 15 years under house arrest between 1989 and 2010. She was awarded the Nobel Peace Prize in 1991.
She remains hugely popular at home despite damage to her international reputation over the plight of Muslim Rohingya refugees.
The new junta has declared a one-year state of emergency, but Min Aung Hlaing told a business group on Wednesday that he could stay on beyond that.
"The army had to take charge for several reasons, but will not go beyond the democratic path," he was quoted as saying by pro-army People Media.
The NLD won about 80% of the parliament seats in the November election and trounced a pro-military party, according to the election commission. The army refused to accept the result, citing unsubstantiated allegations of fraud.
A group of lawmakers who had been due to take up their seats on Monday before the coup stopped them held their own oath-taking session at the complex where they have stayed since then.
The United Nations said it would step up international pressure to ensure the will of the people is respected.
"We will do everything we can to mobilize all the key actors and international community to put enough pressure on Myanmar to make sure that this coup fails," United Nations Secretary-General Antonio Guterres said in an interview broadcast by The Washington Post on Wednesday.
Washington said it was reviewing possible sanctions. U.S. President Joe Biden discussed the situation in calls with the leaders of South Korea and Australia, the White House said.
Norway's Telenor Asa, Myanmar's leading mobile network operator, said it had no choice but to comply with the directive to block Facebook but did not believe the request was based on necessity in accordance with international human rights law.
Facebook spokesman Andy Stone urged authorities to restore connectivity "so that people in Myanmar can communicate with their families and friends and access important information."