Police in Russia detained more than 1,000 people in Moscow Saturday in what was the biggest crackdown of dissent in recent times and a sign that the opposition is becoming more defiant as it stands up to President Vladimir Putin’s stronghold on power. The protesters were demonstrating against the move to exclude opposition candidates from the ballot for Moscow’s city council. Several opposition activists who had sought to run in the September election were arrested before the protest even began. Overall, police arrested 1,074 protesters throughout the long demonstrations that lasted around seven hours, according to Russian state news agencies that cited police figures. An independent monitor cited by the New York Times put the number of arrests slightly lower at 938.

Нагцвардия и полиция избивает дубинками лежащих на земле протестующих

Видео: Медиазона pic.twitter.com/Kgux1ktrsF — Медиазона (@mediazzzona) July 27, 2019

Video posted on social media showed how police clashed with demonstrators and hit protesters with batons as they tried to disperse the crowd and make arrests.

Serious clash on the Tverskaya just off Pushkin square. Pepper has being used pic.twitter.com/P9OE4LK6eD — Ivan Nechepurenko (@INechepurenko) July 27, 2019

The protest Saturday came after authorities appear to have been caught off guard by protests last week against the decision to bar candidates from competing in the September vote. Alexei Navalny, Russia’s most prominent opposition figure, was arrested earlier in the week and was sentenced to 30 days in jail for calling for the protest. Police on Saturday burst into an office that Navalny supporters were using to live-stream the protests.

Although police said some 3,500 people, including around 700 journalists and bloggers, participated in the protest, others say the real number is likely much higher. It also isn’t clear though how many of those detained were actually participating in the protest. Reuters reports some of those detained appeared to be people who were simple “in the wrong place at the wrong time.”