MOSCOW (Reuters) - Russia’s Federal Security Service (FSB) has ordered some of the country’s major internet companies to give it continuous access to their systems, The Bell investigative website reported late on Tuesday, citing three sources at the firms.

FILE PHOTO: Cars drive past the headquarters (C) of the Federal Security Service in central Moscow, May 14, 2013. REUTERS/Maxim Shemetov/File Photo

It said the measure would affect a string of Russian internet services that have been added to a list of entities obliged to hand over user data and messages to Russian law enforcement agencies on request.

The list, drawn up by Russian communications watchdog Roskomnadzor, contains more than 200 entities such as popular messenger service Telegram, some Yandex services, social network VK and classified advertisement website Avito.ru.

Reuters was unable to immediately confirm the report.

The Bell said the orders, which the companies received last year, demanded they install equipment allowing FSB employees to have continuous access to their information systems and the keys to decode users’ communications.

Companies that fail to comply can be blocked.

Russia’s increased regulation of the internet has drawn criticism from some opposition politicians and sparked protests by activists who are concerned about what they say is the state’s growing presence in the online world.

Russia has in the past attempted to block access to the Telegram messenger service after it refused to give state security access to users’ secret messages.

The authorities have also started to focus their attention on foreign services as well, including dating app Tinder.

Tinder said last year that it had agreed to be added to Roskomnadzor’s register but had not divulged users’ personal information. The Bell did not say whether Tinder had been ordered by the FSB to hand over users’ data and communications.