Detained protesters are now thought to be in Insein prison, but have been unable to see lawyers or their families.
Anti-coup demonstrators pushed on with protests on Sunday – as Myanmar neared its seventh week under military rule – with a group of MPs in hiding urging them to move with “invincibility” to overcome the nation’s “darkest moment”.
Witnesses and local media reported that at least two people were killed on Sunday when security forces fired on the protesters.
A young man was shot and killed in the town of Bago, near the commercial capital, Yangon, witnesses and local media said.
Kyaw Swar, a resident and protester from Bago city, told dpa news agency that a fellow demonstrator was killed by a gunshot and that several others were injured.
“Tension has increased,” he said. “People won’t stop protesting and the military forces are trying to crack down.”
The Kachinwaves outlet said another protester was killed in the town of Hpakant, in the jade mining area in the northeast.
On Saturday, four deaths were reported in Mandalay, the country’s second-biggest city, two in Pyay, a town in south-central Myanmar, and one in Twante, a suburb of Yangon.
Details of all seven deaths were posted on multiple social media accounts, some accompanied by photos of the victims.
More than 80 people have been killed in widespread protests against the military’s seizure of power last month, the Assistance Association for Political Prisoners advocacy group said. At least 2,100 people have been arrested.
The acting leader of Myanmar’s parallel civilian government, appointed by legislators who were removed following a power grab by the military in February, has promised to pursue a “revolution” to overturn the military government.
Last week, Mahn Win Khaing Than was appointed as acting vice president by representatives of Myanmar’s overthrown legislators, the Committee for Representing Pyidaungsu Hluttaw (CRPH), which is pushing for recognition as the rightful government.
“This is the darkest moment of the nation and the moment that the dawn is close,” said Mahn Win Khaing Than, who is on the run along with most senior officials from the ruling National League for Democracy party, while addressing the public via Facebook on Saturday.
He said the civilian government would “attempt to legislate the required laws so that the people have the right to defend themselves” against the military crackdown.
The CRPH has announced its intention to create a federal democracy and leaders have been meeting representatives of Myanmar’s largest ethnic armed organisations, which already control vast swaths of territory across the country. Some have pledged their support.
“In order to form a federal democracy, which all ethnic brothers, who have been suffering various kinds of oppressions from the dictatorship for decades, really desired, this revolution is the chance for us to put our efforts together,” Mahn Win Khaing Than said.
His address was greeted with thousands of approving comments from many who followed it on Facebook.
“Keep it up Mr President! You are our hope. We are all with you,” wrote one user, Ko Shan.
The military government has declared CRPH illegal and said anyone involved with it could be charged with treason, which carries the death penalty.
The CRPH has declared the military government a “terrorist organisation”.
“We have seen protesters coming out onto the streets since early morning,” said Al Jazeera’s Tony Cheng, reporting from neighbouring Thailand.
“In Mandalay, there was a brutal crackdown yesterday and yet they came out today. It appears security forces have stepped back there.
“The protesters have realised there is very little they can do in the face of live fire and bullets so they are trying to put up obstructions and using fire extinguishers to block the snipers’ view to give themselves a chance to escape.”
Earlier, the Monywa township in central Myanmar declared it had formed its own local government and police force.
In Yangon, hundreds of people demonstrated in different parts of the city after putting up barricades of barbed wire and sandbags to block security forces.
In one area, people staged a sit-in protest under sheets of tarpaulin rigged up to protect them from the harsh midday sun.
“We need justice,” they chanted.
Security forces fired tear gas shells and then opened fire on protesters in the Hlaing Tharyar district of the city, witnesses said.
“They are acting like they are in a war zone, with unarmed people,” said Mandalay-based activist Myat Thu.
Si Thu Tun, another protester, said he saw two people shot, including a Buddhist monk.
“One of them was hit in the pubic bone, another was shot to death terribly,” he said.
A truck driver in Chauk, a town in the central Magway Region, died after being shot in the chest by police, a family friend said.
The military-run media MRTV’s evening news broadcast on Saturday labelled the protesters “criminals” but did not elaborate.