A mass uprising in Myanmar against a February military putsch has been met with a brutal crackdown that has killed more than 870 civilians, according to a local monitoring group.

Protesters across the country on Saturday donned flowers in their hair -- long a signature Suu Kyi look -- to mark the birthday of the democracy icon, who turned 76 under junta house arrest.

Many replicated the floral hairstyle and uploaded pictures onto social media, from a former beauty queen to rebel soldiers.

Suu Kyi told her lawyers "to convey her thanks and share her wishes for the people", her lawyer Khin Maung Zaw told reporters after the court hearing Monday.

She added that she was "in good health".

The hearing heard testimony that Suu Kyi broke coronavirus restrictions during last year's elections that her National League for Democracy (NLD) party won in a landslide, and illegally imported walkie talkies.

Journalists were barred from the proceedings in the special court in the capital Naypyidaw and an AFP reporter said there was a heavy police presence outside.

Brief meetings with her legal team have been the only channel to the outside world for Suu Kyi -- who remains widely popular in Myanmar -- since she was detained in February.

Last month she used her first in-person court appearance to voice defiance against the junta, affirming that her NLD party would "exist as long as people exist because it was founded for people".

Junta leader Min Aung Hlaing has justified his power grab by citing alleged electoral fraud in the November poll and has threatened to dissolve the NLD.

Suu Kyi's lawyers have said they expect the trial to wrap up by July 26.

The other charges against her include claims that she accepted illegal payments of gold and violated a colonial-era secrecy law.