MOSCOW, Jan. 28 (Xinhua) -- Russian opposition leader Alexei Navalny was detained while attending a protest rally for a boycott of the upcoming presidential race, the Moscow City Police said Sunday.

"The Moscow police have detained Navalny, one of the organizers of an unauthorized public event on Tverskaya Street," the police's press service said, adding the opposition leader was later brought to the district police department for an inquiry.

An administrative offence protocol will be drawn up and filed against Navalny due to his violation of the established procedure of organizing or holding an assembly, rally, demonstration or similar public events, the police said.

According to the police, some 1,000 people participated in the unauthorized rally in the central Tverskaya Street and its vicinity in Moscow.

Earlier in the day, Russian law enforcement officers raided the Moscow office of Navalny's Anti-Corruption Foundation on account of a phone call reporting bomb threat, detaining a number of staff members, the foundation's spokesperson said.

Russia's RIA Novosti news agency reported earlier this week that Navalny's supporters had submitted an application to the Moscow municipal government on holding protests on Sunday involving 15,000 people at the downtown of Moscow, which was later rejected.

Navalny has been calling on voters to boycott the presidential race scheduled for March 18, which he claimed to be a rigged "pseudo election."

Russia's Supreme Court rejected an appeal by Navalny and upheld a ban on his participation in the 2018 presidential election for his conviction of embezzlement at a timber company.

A total of over 5,000 people attended rallies held by Navalny's supporters in other cities of Russia on Sunday, the Russian Presidential Council for the Civil Society Development and Human Rights said in a statement.