Russian opposition leader Alexei Navalny has been detained by police.
Navalny said on social media on Friday that police had detained him in the lobby of his apartment block and told him they wanted to interview him at a police station.
He had been on his way to attend a pre-election rally in a provincial town.
The press service of Moscow’s interior ministry says Navalny had been detained due to his “repeated calls to take part in unsanctioned public events.”
The authorities say opposition protests must be pre-approved by them, but Navalny has in the past said that the Russian constitution enshrines the right to freely hold such events.
Navalny had been due to address a pre-election rally in the city of Nizhny Novgorod later on Friday, part of a series of regional events he hoped would help him build support for his presidential run.
Russia holds a presidential election in March, which incumbent Vladimir Putin is widely expected to contest. Navalny hopes to run despite Russia’s central election commission declaring him ineligible because of a suspended prison sentence which he says was politically-motivated.