MOSCOW -- Russia's communications watchdog agency says it is adding some Google IP addresses to the state register of banned sites, as a dispute over a banned messaging app intensifies.

Russia has ordered the popular Telegram messaging app to shut down because it won't share its encryption key with intelligence agencies. Communications watchdog Roskomnadzor then blocked 18 networks that are used by Amazon and Google and host sites it believe Telegram is using to circumvent the ban.

That move blocked access to millions of sites, including many Russian businesses.

On Sunday, Roskomnadzor raised the stakes by announcing it had added an unspecified number of Google IP address used by Telegram to the register of banned sites.

Google has long ignored a Roskomnadzor demand to store personal data on Russian servers.