A block on mobile data networks across Myanmar on Monday scuppered a scheduled video court appearance by ousted leader Aung San Suu Kyi, as protesters returned to the streets after the bloodiest day since the military coup six weeks ago.

The court hearing for Suu Kyi -- who spent more than 15 years under house arrest during previous military rule -- was scheduled for 10 am (0330 GMT) in Myanmar's capital Naypyidaw, but it was postponed until March 24, her lawyer Khin Maung Zaw told AFP.

"There's no court hearing because there's no internet and the hearing is conducted by video conference... We cannot do video," he said.

Myanmar authorities have throttled the internet every night for several weeks, normally restoring services in the morning, but monitoring service Netblocks said mobile data networks were kept offline Monday.

Suu Kyi faces at least four charges: possessing unlicensed walkie-talkies, violating coronavirus restrictions, breaching telecommunications laws, and intent to cause public unrest.

Military authorities have also accused her of accepting illegal payments of $600,000 in cash as well as a large quantity of gold -- allegations her lawyer says are "groundless".

Khin Maung Zaw had previously complained he was not allowed to meet Suu Kyi, who has been in custody since the coup, and on Monday said police have appointed two junior lawyers on his team to have the power of attorney.

"The police have no right to decide who represents the defendants," he said, adding that the whole situation is "strange" -- from the lack of Wi-Fi in the court to the appointment of junior lawyers.

© AFP