MOSCOW >> Russian authorities are freezing up vast swathes of the country’s online world in what critics call a heavy-handed — and so far unsuccessful — attempt to block a popular messaging app, Telegram.

The head of the communications watchdog acknowledged Wednesday that millions of IP addresses unrelated to Telegram have been blocked since a court ordered last week that the app be taken offline.

The move has created trouble for millions of companies and consumers, and was described by some as “carpet bombing” the internet to get after one small company. Telegram was still available in Russia despite authorities’ frantic attempts to hit it by blocking other services, but many users are preparing for the worst, setting up proxies to circumvent the ban.

The row erupted after Telegram, which was developed by Russian entrepreneur Pavel Durov, refused to hand its encryption keys to Russia’s intelligence agencies. The Russian government insists it needs them to pre-empt extremist attacks but Telegram dismissed the request as a breach of privacy.

Alexander Zharov, chief of the Federal Communications Agency, told the Izvestia daily in an interview published today that Russia is blocking 18 networks that are used by Amazon and Google and which host sites that they believe Telegram is using to circumvent the ban.

Countless Russian businesses — from online language schools to car dealerships — reported that their web services were down because of the communication watchdog’s moves to bloc networks.

Internet experts estimate that Russian authorities have blocked about 16 million IP addresses since Monday, affecting millions of Russian users and businesses.

In the interview, Zharov admitted that the authorities have been helplessly trying to block Telegram and had to shut down entire networks, some of which have over half a million IP addresses that are used by unrelated “law-abiding companies,” he said.

Russia’s leading daily Vedomosti in today’s editorial likened the communications watchdog’s battle against Telegram to warfare.

“The large-scale indiscriminate blocking of foreign IP addresses in Russia in order to close the access to the messaging app Telegram is unprecedented and bears resemblance to carpet bombings,” the editorial said.

Zharov also indicated that Facebook could be the next target for the government if it refuses to comply with Russian law.

Authorities previously insisted that Facebook store its Russian users’ data in Russia but has not gone through with its threats to block Facebook if it refuses to comply.

Zharov said authorities will check before the end of the year if the company is complying with its demands and warned that if it does not, “then, obviously, the issue of blocking will arise.”

Thousands of small businesses have used Telegram for many reasons, from advertising cheap airline tickets to offering advice on the stock markets.

Among the countless victims of Telegram’s ban is a small Moscow-based education project which uses the app’s bot platform to engage users in tasks and foster creative thinking.

Solomon Shlosman, co-founder of the MOST Creative Camp, said Wednesday he set out “to do something good for my country and to contribute to people living here . but they — the government — are preventing me from doing this. Blocking is what they did in the Soviet times and now they are doing it again.”

Shlosman said the ban on Telegram got him thinking about translating the coursework into English and trying to attract an English-speaking audience.

While free speech and political discourse have been shrinking in traditional Russian media for years, the internet remained a truly free platform for debate and communication, where users could express their opinions. That changed several years ago when Russian authorities started blocking websites of opposition politicians, and the courts began to send activists to jail for social media posts.

While Telegram remains widely available in Russia, many users are preparing for it to go offline, setting up virtual private networks that would allow them to bypass local restrictions.

To Nikita Likachyov, editor-in-chief of the Russian online tech magazine T Journal, the Telegram ban is a watershed moment for the Russian internet community. Public reaction to the ban will show if the community can come up with “successful counter-measures against the decision,” Likhachyov said.

How effective the government is in blocking Telegram can determine the future of other social media platforms.

“If they go full house on Telegram, it means they can go full house on YouTube and Facebook,” he said.

But, Lykachyov says, the fact that the rebel messaging app is still up and running shows that government agencies are not competent enough to enforce the ban.

“The government has put so much pressure on trying to get control of the internet and still it doesn’t understand how it works — in terms of the spirit and freedom. You cannot tame that beast, and we don’t want to give it up,” he said.

Several small demonstrations against the ban were held this week in Moscow and St. Petersburg, and some Telegram supporters were detained.

A court today sentenced a member of the punk collective Pussy Riot who had spent nearly two years in prison for a protest in Russia’s main cathedral to 100 hours of community service for a protest against the Telegram block. Maria Alekhina and a dozen activists were throwing paper planes outside the communications watchdog’s office on Monday.