Russian police have detained more than 700 people at anti-war protests across dozens of cities after President Vladimir Putin sent troops to invade Ukraine, an independent monitor said Thursday.
Around 2,000 people gathered near Pushkin Square in central Moscow, while up to 1,000 people gathered in the former imperial capital Saint Petersburg, according to AFP correspondents at the scene.
The invasion of Ukraine is taking place during an unprecedented crackdown on the Russian opposition, with most protest leaders assassinated, jailed or forced out of the country.
Jailed opposition leader Alexei Navalny, who used to mobilise Russia's largest protests against Putin, is serving a two-and-a-half-year sentence in a penal colony outside Moscow.
A number of Russian activists called on social media for people to take to the streets after Putin launched an offensive on Ukraine in the early hours of Thursday.
In Moscow, protesters were seen massing around Pushkin Square chanting "No to war!"
"I am in shock. My relatives and loved ones live in Ukraine," Anastasia Nestulya, 23, said in Moscow.
"What can I tell them over the phone? You hang in there?"
She said many were afraid to protest.
In Saint Petersburg, many struck a similar note.
"I have a feeling that the authorities have gone mad," said Svetlana Volkova, 27. She also said few people were willing to protest in Russia.
"People have been fooled by propaganda."
As he was dragged away by three police officers, a young man shouted: "Who are you fighting with? Arrest Putin."
In recent years Russia has toughened protest laws, and demonstrations often end in mass arrests.
Earlier Thursday, Navalny said he was against the invasion of Ukraine.
"I am against this war," Navalny was heard saying in a video published by the independent television channel Dozhd.
"This war between Russia and Ukraine was unleashed to cover up the theft from Russian citizens and divert their attention from problems that exist inside the country," the 45-year-old said.
Earlier Thursday, Russian authorities warned anti-war sympathisers from gathering for protests.
The Investigative Committee, a government body that investigates major crimes, warned Russians of legal repercussions for joining unsanctioned protests related to "the tense foreign political situation".
"One should be aware of the negative legal consequences of these actions in the form of prosecution up to criminal liability," the committee said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
Track Latest News Live on NDTV.com and get news updates from India and around the world