The Russian government has started to block messaging app Telegram, according to reports from the local news agency Tass.

Russia's media regulator had sought to block the app because the firm has refused to hand over encryption keys used to scramble messages.

Telegram had missed a deadline of 4 April to hand over the keys.

The company said the way the service was built meant it has no access to customers' encryption keys.

Russia's main security agency, the FSB, had said it wants access to the keys so it can read messages and prevent future terror attacks in the country.

Aida AYSA,

“Khalg gazeti”