From Moscow to Siberia, Russian anti-war activists took to the streets again Sunday to protest Russia’s invasion of Ukraine, despite the arrests of hundreds of protesters each day by police.

Demonstrators held pickets and marched in city centres, chanting “No to war!” as President Vladimir Putin ordered Russian nuclear deterrent to be put on high alert, upping the ante in the Kremlin’s standoff with the West and stoking fears of a nuclear war.

“I have two sons and I don’t want to give them to that bloody monster. War is a tragedy for all of us,” 48-year-old Dmitry Maltsev, who joined the rally in St. Petersburg, told The Associated Press.

Protests against the invasion started Thursday in Russia and have continued daily ever since, even as Russian police have moved swiftly to crack down on the rallies and detain protesters. The Kremlin has sought to downplay the protests, insisting that a much broader share of Russians support the assault on Ukraine.