Apple has caved to pressure from Russian authorities and removed a number of the best iPhone VPN apps from the App Store in the country.

Apple's App Store team has been notifying VPN developers that their apps are being removed "per demand from Roskomnadzor." This the state media watchdog that previously forced both Apple and Google to remove a political app backed by the leader of the country's opposition.

According to the Moscow Times, the Roskomnadzor regulator based its demand on how the apps include "content that is illegal in Russia." It also reports that this demand to remove mobile apps follows the regulator's increasing blocking of VPN services.

Details of Apple's App Store notifications come from emails sent to two VPN developers. According to Reuters, however, as many as 25 such firms have now had their apps removed.

Reportedly, VPN usage increased dramatically in Russia following the start of the war with Ukraine. At that point, Russian authorities blocked access to a number of Western social media sites.

Virtual Private Networks are intended to encrypt a user's data for security reasons, but they have the added benefit that they disguise where a user is. So, using one of the services, location can't be tracked by the government. Once set up on an iPhone, the user can therefore bypass local — on in this case, country-wide — restrictions on sites.