"The Internet has not been working since yesterday. My friend also tried to use the Internet, but could not do so," said a Yangon resident.
She said Internet cafes in Yangon remained closed.
Over the past week, the net cafes drew tech-savvy citizens who transmitted pictures and video clips of the regime's clampdown taken on mobile phones and digital cameras.
As the government has cracked down on protesters, killing at least 13 people and injuring hundreds more, pressure on the media has soared. Sein Win, managing editor of Mizzima News, an India-based news group run by exiled dissidents, said he had received nothing via the Internet since yesterday.
"The Internet remained shut down. It's very frustrating," Sein Win said.
An editor of the Thai-based opposition publication Irrawaddy news also said the Internet link was down today.
In Yangon, soldiers shot dead a Japanese video-journalist Thursday and beat people found with cell phones or cameras, witnesses said.
Myanmar's military rulers always keep a tight grip on information, heavily censoring newspapers, blocking much of the Internet and rarely allowing foreign journalists into the country.
Paris-based Reporters Without Borders has called Myanmar a "paradise for censors" and listed the country as one of the world's most restrictive for press freedoms.