“It seems like the internet shutdown is only for the military’s sake,” he added. “It destroys the rule of law and security.”

The online blackout for cellphones, which began on June 21 and affects eight townships in Rakhine State and one in neighboring Chin State, “is depriving aid workers and rights monitors of vital communications in a time of crisis,” said Brad Adams, Asia director at Human Rights Watch.

Telenor Myanmar, one of the nation’s largest cellular providers, said in a statement that “freedom of expression through access to telecoms services should be maintained for humanitarian purposes, especially during times of conflict.”

The United States joined the condemnation, saying that the shutdown “has curtailed some forms of internet-based communication for as many as one million people,” according to a statement by Morgan Ortagus, a spokeswoman for the State Department.

“Internet service should be restored without delay,” Ms. Ortagus said, to “limit further damage to Burma’s international reputation.”

The United States refers to Myanmar by its previous name, Burma.

Once hailed for what its army leaders portrayed as a peaceful transition toward democratic governance, Myanmar has had its reputation battered by continuing military aggression, most notably against ethnic minorities, who make up at least one third of the nation’s population.