More than a thousand people were detained by Russian authorities on Thursday after citizens across the country flocked to the streets to protest the invasion of Ukraine. Cries of “No to war!” could be heard among protesters in Moscow’s central Pushkinskaya Square, where police blocked off access and rounded up roughly 600 people, according to The New York Times. A further 170 demonstrators were detained in St. Petersburg, Russia’s second-largest city, according to OVD Info, a rights media project tracking arrests. The organization reported that more than 1,300 people had been arrested across Russia. Those taken into custody included Marina Litvinovich, a well-known human rights activist, who posted a video on social media calling for Russians to take to the streets. Numerous Russian law enforcement agencies had warned citizens against protesting earlier on Thursday. The powerful Investigative Committee released a statement threatening “the negative legal consequences of these actions,” including criminal prosecution. “Everyone must be here, it is the only way to show that something monstrous is happening,” an emotional protester in Moscow told the Times.