MOSCOW (AP) — Many foreign websites were blocked Friday on mobile phones in central Moscow under restrictions that have gripped the Russian capital for more than a week, derailing the routine of millions of residents and slamming businesses that rely on cellphone internet.

Russian authorities have said the restrictions are part of security measures to fend off Ukrainian drone attacks, but many industry experts suspect they are part of preparations by the authorities to block Russians’ access to the global web if the Kremlin decides to do so.

The intermittent shutdowns, which had previously been recorded in dozens of Russia’s regions for months, have prompted some Moscow residents to turn to long-forgotten gadgets like walkie talkies, pagers and media players.

The shutdowns are part of multipronged efforts by the authorities to rein in the internet. They have adopted restrictive laws and banned websites and platforms that don’t comply. Technology also has been perfected to monitor and manipulate online traffic.

After President Vladimir Putin sent troops into Ukraine in February 2022, the government has blocked major social media sites like Twitter, Facebook and Instagram. Last year, Russia’s communications watchdog announced it was restricting popular messaging apps WhatsApp and Telegram.

At the same time, authorities have actively promoted a “national” messenger app called MAX, which critics see as a surveillance tool.

The mobile internet shutdowns in Moscow, which were first reported on March 5 on some of the capital’s outskirts, swept through the downtown area earlier this week. Many other regions have been hit with connectivity blackouts since May.

During the outages, a number of government-approved Russian websites and online services have been designated as being on “white lists” and have been available. But during this week’s cellphone internet disruptions in Moscow, even white-listed government services, top banks and taxi apps stopped functioning.

Businesses with broadband access, and residents with broadband at home, have not been affected.

However, owners of Moscow cafes, restaurants and shops that rely on mobile internet have suffered massive losses as customers have been unable to pay for the services. The ATMs and parking meters that rely on cellphone internet stopped working.

Taxi apps have offered clients the option of calling a taxi by phone and paying cash.

During some moments, not only cellphone internet but cellphone coverage for making calls was halted completely.

Earlier this week, members of the Kremlin-controlled parliament reported that mobile internet was almost entirely missing in the lower house building located just a few hundred meters (yards) from Red Square.

On Friday, Russian websites and some mobile apps were available in central Moscow, but foreign websites were blocked in what some observers saw as part of dress rehearsals for cutting off access to the Web.

The business daily Kommersant published an estimate earlier in the week that Moscow businesses lost between 3 and 5 billion of rubles (about $38 million to $63 million) in five days of shutdowns. Other estimates ran significantly higher.

Media reports said that as shutdowns gripped Moscow, retailers recorded a quick surge in demands for pagers, portable radios, stationary phones and media players.

Kremlin spokesman Dmitry Peskov said on Wednesday that latest cellphone internet shutdown in Moscow was in “strict conformity with the law” and would last “as long as additional measures to ensure security of our citizens are necessary.”

Recently approved legislation has obliged Russian internet providers to shut down mobile internet when the authorities declare it necessary for security reasons.

Asked why the shutdowns in Moscow were taking place now, Peskov responded that as Ukraine launches “increasingly sophisticated methods of attack, the more technologically advanced measures are needed to ensure public security.”

He said that the government will look at ways to compensate businesses for the losses resulting from the shutdowns, but offered no specifics.