NetBlocks, which monitors internet traffic, said the blackout began at 10 a.m. local time (3:30 GMT).

"Myanmar is now in the midst of a second nation-scale internet blackout… real-time network data show national connectivity falling to 54% of ordinary levels as users report difficultly getting online," it said.

The military blocked Twitter, Instagram and Facebook until further notice after accusing social media of spreading fake news. Telenor, a major internet provider, said on Friday it was concerned by this development.

A Twitter spokesperson told the TechCrunch news website that the outage undermined the rights of people to make their voices heard and promised to advocate for an end to government-led shutdowns.

"We understand some people across the Asia-Pacific region may also be having trouble accessing Twitter, and we’re working to fix it," they added.

Social media users from Myanmar posted photos from protests against the military rule that broke out in Myanmar’s largest city of Yangon on Saturday morning.

The army overthrew the democratically elected government on Monday after accusing the party of its de facto leader, Aung San Suu Kyi, of rigging the November elections.