MOSCOW (AP) — Russia's communications watchdog says it is blocking access to some servers owned by tech giants Google and Amazon in order to comply with a court order to block a popular messaging app.

The Russian Communications Agency on Monday began enforcing a court ban on the messaging app Telegram over its refusal to hand over encryption keys. Telegram, which was developed by Russian entrepreneur Pavel Durov, has refused to share data, citing privacy concerns. It has promised to keep the app running despite the ban.

The Russian communications watchdog told the Interfax news agency Tuesday it was blocking a "significant number" of servers owned by Google and Amazon because it believes that Telegram is using them to circumvent the ban.

Dozens of Russian online stores have reported problems with their services.