YANGON: Ousted Myanmar civilian leader Aung San Suu Kyi was hit with two new criminal charges in a court appearance via video link on Monday, one month after a military coup triggered relentless mass protests.

Suu Kyi has not been seen in public since being detained on February 1, and her court appearance came as demonstrators marched across the country defying an escalation of deadly force by the junta.

At least 18 people were killed Sunday as troops and police fired at demonstrators in cities across Myanmar, according to the United Nations, which cited its own credible information.

State broadcaster MRTV said late Monday that more than 1,300 people were arrested and eleven killed on Sunday, adding that security forces have been directed not to use live rounds against protesters.

Suu Kyi, 75, was already facing obscure criminal charges for possessing unlicensed walkie-talkies, as well as violating coronavirus restrictions by staging a campaign event during last year's election.

She is now also accused of breaching communications laws as well as intent to incite public unrest, her lawyer Khin Maung Zaw said.

"We cannot say for sure how many more cases Daw Aung San Suu Kyi will face in this period," he told reporters in Naypyidaw.

Suu Kyi has reportedly been kept under house arrest in the capital of Naypyidaw, an isolated city purpose-built under Myanmar's previous junta.

The military has justified its takeover, which ended a decade-long democratic experiment, with unfounded allegations of widespread fraud in last November's national elections, which Suu Kyi's National League for Democracy won in a landslide.

A committee of deposed lawmakers from her party on Monday said that due to the "atrocities and acts of terrorism of the military the streets and communities across Myanmar have become battlefields."