Russian police have cracked down fiercely on demonstrators in central Moscow, arresting more than 1,000 people who were protesting against the exclusion of some opposition candidates from an upcoming election to the city council.

Police confronted protesters around the mayor’s office, sometimes charging into the crowd with their batons raised. State news agencies Tass and RIA-Novosti cited police as saying 1,074 were arrested over the course of the protests, which lasted more than seven hours.

Along with the arrests of the mostly young demonstrators, several opposition activists who wanted to run for the council were detained throughout the city before the protest.

Russia protestA man is removed from the scene by officers (Alexander Zemlianichenko/AP)

Alexei Navalny, Russia’s most prominent opposition figure, was sentenced on Wednesday to 30 days in jail for calling an unauthorised protest.

The protesters, who police said numbered about 3,500, shouted slogans including “Russia will be free” and “Who are you beating?”

One young woman was seen bleeding heavily after being struck on the head.

Helmeted police also barged into Navalny’s video studio as it was conducting a YouTube broadcast of the protest and arrested programme leader Vladimir Milonov.

Russia protestOpposition candidates Ivan Zhdanov and Yuliya Galyamina attended the protest (Alexander Zemlianichenko/AP)

In addition, police searched Dozhd, an internet TV station that was covering the protest, and its editor-in-chief Alexandra Perepelova was ordered to undergo questioning at the Investigative Committee.

Police eventually dispersed protesters from the area of the mayor’s office, but many demonstrators reassembled at a square nearby, where new arrests began.

Police were seen beating some to the ground with wide truncheon swings while other demonstrators tried to push them away.

Russia protestPolice officers detain a woman in Moscow (Alexander Zemlianichenko/AP)

Before the protest, several opposition members were detained, including Ilya Yashin, Dmitry Gudkov, Lyubov Sobol and top Navalny associate Ivan Zhdanov. All were released later in the day and Zhdanov and Sobol went to the relocated protest and were detained again.

There was no immediate information on what charges the detainees might face.

Once a local, low-key affair, the September vote for Moscow’s city council has shaken up Russia’s political scene as the Kremlin struggles with how to deal with strongly opposing views in its sprawling capital of 12.6 million.

Russia protestProtesters are angry some opposition candidates in a Moscow council election have been excluded from standing (Alexander Zemlianichenko/AP)

The decision by electoral authorities to bar some opposition candidates from running for having allegedly insufficient signatures on their nominating petitions had already sparked several days of demonstrations even before Saturday’s clashes in Moscow.

The city council, which has 45 seats, is responsible for a large municipal budget and is now controlled by the pro-Kremlin United Russia party.

All of its seats, which have a five-year-term, are up for grabs in the September 8 vote.