Signal app is seen on a smartphone in this illustration taken, July 13, 2021. REUTERS/Dado Ruvic/Illustration/File Photo
MOSCOW (Reuters) -Russia's state communications watchdog Roskomnadzor said that Signal, an encrypted messaging app, had been blocked in the country for violating laws linked to anti-terrorist operations, Interfax news agency reported on Friday.
"Access to the Signal messaging app is blocked in connection with violation of the requirements of Russian legislation which must be complied with to prevent the use of messaging apps for terrorist and extremist aims," Interfax quoted the agency as saying.
Prior to Roskomnadzor's announcement that it had taken action, hundreds of Signal users reported glitches with the messenger app, a secure communications tool used by up to a million Russians to encrypt messages and conversations.
Internet service monitoring sites showed more than 1,500 complaints about Signal, mostly from users in Moscow and St Petersburg. Users reported, however, that it was working normally when accessed via a VPN or used in the built-in censorship bypass mode.
"This indicates precisely a blocking of the messenger in Russia and not a technical problem on the Signal side," Mikhail Klimarev, author of the Telegram channel "For Telecom", told Reuters.
Signal did not reply to a request for comment.
It was also impossible to register a new account on Signal without a VPN, three people from Moscow and the Krasnodar region told Reuters. When entering a mobile number, the service displayed the message "Server Error".
Klimarev said it was the first attempt to block Signal in Russia.
Russian authorities began to block access to Telegram, a widely used messaging app, in 2018. The action interrupted many third-party services, but had little effect on the availability of Telegram in Russia.
(Writing by Felix Light; Editing by Alex Richardson and Ron Popeski, Kirsten Donovan)