Around 700,000 people in Myanmar are estimated to have lost internet access after attacks on telecommunication equipment run by Mytel, the partly army-controlled company said, amid reports that dozens of its towers were damaged.
The explosions have occurred since the National Unity Government (NUG), a shadow administration formed to resist the army's Feb 1 coup, declared last week a "people's defensive war" against the junta.
Myanmar has been in turmoil since Aung San Suu Kyi's government was toppled, sparking nationwide anger, strikes, protests, and the emergence of anti-junta militia.
There has been an upsurge in bloodshed in some areas after the underground NUG declared an uprising and called on the new militia, known as People's Defence Forces (PDF), to target the junta and its assets.
"The destruction of telecommunications infrastructure is depriving the means to access information, education, and important services on the internet for hundreds of thousands," said a spokesperson for Mytel, a venture between Myanmar's army and Viettel, which is owned by Vietnam's defence ministry.
Most attacks have been in rural areas and more than 80 towers owned by Mytel have been destroyed, with People's Defence Forces claiming responsibility in some areas, according to a report by the independent Irrawaddy newspaper this week.
A military spokesman did not respond to a request for comment, but an army newsletter published on Sep 12 listed 68 explosions at public telecommunication towers.
It did not specify who they belonged to and accused the "NUG terrorist organisation" of promoting violence.
Videos on social media have shown what appear to be blasts at towers. Reuters could not immediately confirm with any PDFs whether they had carried out the attacks.
Earlier in the conflict, the military had at times itself shut down the internet, particularly in cities, in a bid to curb demonstrations.
The declaration of an uprising came amid opposition frustration at lack of concrete support from around the world in opposing the junta.
"Now people have realised that we must walk till the end regardless of international assistance or not," NUG deputy minister Maw Htun Aung said in a text message.
Still, while the NUG has received a barrage of support on social media in Myanmar, it remains unclear how much its declaration will threaten a well-equipped military.
"I will have high hopes in our revolution if all of the PDFs around the country rise up in arms. But for now, they are not ready," said a 27-year-old supporter of the Chinland Defence Force, set up in Chin state bordering India.