Protesters in Myanmar on Thursday marked two months since the military seized power by once more defying the threat of lethal violence and publicly demonstrating against the toppling of the democratically elected government.

The February 1 coup has been met with massive public resistance that security forces have been unable to crush through escalating levels of violence, including now routinely shooting protesters.

Outside efforts including sanctions imposed by Western nations on the military regime have failed to help restore peace.

In Yangon, the country’s biggest city, a group of young people shortly after sunrise Thursday sang solemn songs honouring the more-than 500 protesters killed so far.

They then marched through the streets chanting slogans calling for the fall of the junta, the release of deposed leader Aung San Suu Kyi and the return of democracy.

Protests were also held in Mandalay and elsewhere.

The demonstrations followed a night of violence including police raids and several fires.

In Yangon, several retail shops owned in whole or part by Myanma Economic Holdings Limited, which is an investment arm of the military, went up in flames. The shops are the targets of boycotts by the protest movement.

The crisis has expanded sharply in the past week, both in the number of protesters killed and with the military launching airstrikes against the guerrilla forces of the Karen ethnic minority in their homeland on the border with Thailand.

The UN special envoy for Myanmar warned the country faces the possibility of civil war.

Christine Schraner Burgener also urged the UN Security Council to consider “potentially significant action” to restore democracy.

Ms Burgener did not specify what action she considered significant, but she painted a dire picture of the military crackdown and told the council in a closed briefing that Myanmar “is on the verge of spiralling into a failed state”.

A virtual presentation of the briefing was obtained by The Associated Press.

Any UN resolutions for concrete action such as a comprehensive ban on weapons sales to Myanmar would almost certainly be vetoed by China or Russia, who are political allies of the junta as well as major suppliers of arms to its military.

Inside Myanmar, an opposition group made up of ousted lawmakers on Wednesday declared the country’s 2008 constitution void and put forward an interim replacement charter in another challenge to the ruling junta.

The moves, while more symbolic than practical, could help woo the country’s armed ethnic militias to ally themselves with the mass protest movement based in cities and towns.