Russia's media watchdog demands US-based microblogging service Twitter block several "extremist" accounts as the Kremlin continues to tighten its control over the Internet

Russia's media watchdog on Monday demanded US-based microblogging service Twitter block several "extremist" accounts as the Kremlin continues to tighten its control over the Internet.

Agency head Alexander Zharov earlier in the day met with Twitter's public policy chief Colin Crowell a month after Moscow threatened to block the service if it did not comply with new stringent rules.

Zharov gave Crowell "detailed information about 12 accounts whose content has been identified as " and is now expecting Twitter to delete or block them, the agency said in a statement.

Some of the accounts are affiliated with Ukraine's Right Sector, a radical nationalist group that helped to overthrow Kiev's former government which is banned in Russia, media reported.

Moscow recently passed new legislation tightening Internet regulation, including banning circulation of information about mass protests, illegal drugs and suicide, among other subjects.

A law that goes into effect on August 1 requires any social network account with over 3,000 followers to register with the authorities as and makes them liable for third-party comments.

Moscow can now block websites deemed either extremist or a threat to public order without a court ruling.

In an interview with Izvestiya daily last month, Maksim Ksenzov, a deputy of Zharov, accused Twitter of "using bloggers for political ends" and threatened to ban it and Facebook if they do not comply with the new rules and remain a "danger".

Twitter is widely used by Russia's political opposition, with one of the most popular users being the account of Kremlin critic Alexei Navalny, who boasts about 668,000 followers.

The company said it received 31 requests to remove accounts last year from Moscow.

Russia's authorities has a blacklist of organisations it deems "extremist" based on a law targeting groups ranging from Islamic fundamentalists to Nazi groups and Jehovah's witnesses.

Media regulator Roskomnadzor blocked websites of Right Sector earlier this year over calls for "extremist" and "anti-Russian" actions by its leader during violent protests in Kiev that toppled its pro-Russian president.

The watchdog said in the statement that Twitter has agreed to appoint a representative in Russia who will liaise with the authorities.

A company spokesman said Twitter has no plans to open an office in Russia, but declined to give details of the talks.