Scores of people have been arrested in the centre of Moscow while trying to gather for an unauthorised protest demonstration called for by an extreme nationalist group.

The arrests at Manezh Square, adjacent to the Kremlin, on Sunday, came two days after the domestic security agency said it had arrested some group members who are suspected of planning to firebomb administrative buildings.

The group, called Artpodgotovka, was declared an extremist group by a Russian court last week.

Its exiled leader, Vyacheslav Maltsev, had called for protests to force President Vladimir Putin's resignation.

The OVD-Info organisation that monitors political arrests said at least 86 people were detained on Sunday. State news agency Tass cited a police official as saying that about 200 were being held.