The UN special envoy on Myanmar has warned of the potential for an escalation of violence in the country on Wednesday, as anti-coup protesters are expected to face off once again with the military.

The warning comes after deposed civilian leader Aung San Suu Kyi was slapped with a second charge on Tuesday -- and the UN rapporteur hinted she may have even secretly been put on trial.

In the two weeks since troops ousted Aung San Suu Kyi and took the civilian leader into custody, big urban centres and isolated village communities alike have been in open revolt
In the two weeks since troops ousted Aung San Suu Kyi and took the civilian leader into custody, big urban centres and isolated village communities alike have been in open revolt AFP / STR

Myanmar was plunged into an internet blackout for the third night running, Britain-based monitoring group NetBlocks said, as the generals try to wear down the anti-coup uprising.

In the two weeks since the military ousted Suu Kyi and put her under house arrest in the administrative capital Naypyidaw, big cities and isolated village communities alike have been in open revolt.

But Tom Andrews, the UN special rapporteur for Myanmar, said he was worried the situation was spiralling out of control.

Myanmar protests continue as Suu Kyi to face court this week
Myanmar protests continue as Suu Kyi to face court this week AFPTV / AFPTV teams

"I fear that Wednesday has the potential for violence on a greater scale in Myanmar than we have seen since the illegal takeover of the government on February 1," Andrews said in a statement.

He said he had "received reports of soldiers being transported into at least Yangon from outlying regions".

"In the past, such troop movements preceded killings, disappearances, and detentions on a mass scale," he said.

Suu Kyi has not been seen in public since she was detained at the start of February
Suu Kyi has not been seen in public since she was detained at the start of February AFP / Sai Aung Main

"I am terrified that given the confluence of these two developments -- planned mass protests and troops converging -- we could be on the precipice of the military committing even greater crimes against the people of Myanmar."

The shutdown came after another day of protests in Yangon
The shutdown came after another day of protests in Yangon AFP / Ye Aung THU

The military justified its power seizure by alleging widespread voter fraud in November elections won by Suu Kyi's party.

After her detention in a dawn raid on February 1 -- the day of the coup -- Suu Kyi was charged under an obscure import and export law, over walkie talkies that were found in her home.

Troops have fanned out around the country in recent days and fired rubber bullets to disperse one rally in Mandalay
Troops have fanned out around the country in recent days and fired rubber bullets to disperse one rally in Mandalay AFP / STR

The Nobel laureate's lawyer told AFP on Tuesday she had been hit with a second charge, of violating the country's disaster management law.

"She was charged under section 8 of the Export and Import law and section 25 of the Natural Disaster Management law as well," Khin Maung Zaw told AFP.

While it was unclear how the disaster law applied in Suu Kyi's case, it has been used against deposed president Win Myint -- also arrested on February 1 -- relating to a campaign event that the junta alleges broke coronavirus-related restrictions.

Factfile on the military coup in Myanmar
Factfile on the military coup in Myanmar AFP / John SAEKI

Khin Maung Zaw added that Suu Kyi and Win Myint, both of whom he has yet to have any contact with, were expected to appear via video conference during a March 1 trial.

But Andrews said he had "word that a secretive trial" of Suu Kyi and deposed president Win Myint had begun this week, without offering more details.

Military spokesman Zaw Min Tun said Tuesday that both Suu Kyi and Win Myint were in a "safer place" and "in good health".

Myanmar's deposed leader Aung San Suu Kyi is hit with another charge, after the military imposed a second straight overnight internet shutdown in an attempt to grind down an anti-coup uprising
Myanmar's deposed leader Aung San Suu Kyi is hit with another charge, after the military imposed a second straight overnight internet shutdown in an attempt to grind down an anti-coup uprising AFPTV

"It's not like they were arrested -- they are staying at their houses," the general, who became the country's vice-minister of information after the coup, told a press conference.

The United States and Britain condemned the new charge against Suu Kyi, and renewed demands for her release.

More than 420 people have been arrested since the coup, according to a list of confirmed detentions from the Assistance Association for Political Prisoners monitoring group.

Security forces have used increasingly heavy measures to quell huge nationwide street protests and a disobedience campaign encouraging civil servants to strike.

Troops have fanned out around the country in recent days.

Rubber bullets, tear gas and even sling shots have been used against protesters.

"They shut down the internet because they want to do bad things," Win Tun, a 44-year-old who lives in the commercial capital Yangon, said Tuesday.

Undeterred, crowds returned to the streets of Yangon and around the country on Tuesday.

"I want more people to join the protests, we don't want to be seen as weak," said university student Thwe Ei Sann.

A large crowd blocked railway tracks outside Mawlamyine to prevent a Yangon-bound train from leaving the port city.

Many of the country's train drivers have joined the anti-coup work boycotts, frustrating junta efforts to restart the national railway network after a Covid-19 shutdown.

The United States and Britain were not alone in their condemnation of the leaders of Myanmar's new military administration, which insists it took power lawfully.

The Chinese ambassador to Myanmar said Tuesday that "the current development in Myanmar is absolutely not what China wants to see".

Military spokesman Zaw Min Tun said that "sanctions are expected", and that the regime would continue to "maintain friendly relations" with the international community.