Alexei Navalny, Russia’s most prominent opposition figure, has been detained by police and charged with unlawfully organising a public gathering.

Mr Navalny has called for demonstrators to protest on Saturday outside the mayor’s office against the rejection of several opposition candidates from the ballot for this autumn’s Moscow city council elections.

In a short video on social media, Mr Navalny said he was seized by police outside his home on Wednesday as he went out for a run and to buy flowers for his wife’s birthday.

His lawyer Olga Mikhailova told the Interfax news agency that he had been charged with organising an unauthorised gathering.

Conviction could carry a penalty of 30 days in jail and a fine of up to 300,000 rubles (£3,800).

After the candidates for city council were rejected on the grounds of invalid signatures on their nominating positions, protesters held an unsanctioned demonstration outside the city election commission.

Russia’s investigative committee on Wednesday said it was opening a criminal case over that demonstration, although potential charges were not specified.