Police detained more than 400 people who protested at unauthorized rallies in Moscow and St. Petersburg against the imprisonment of seven opposition activists, the Interior Ministry has said.
About 500 people gathered in central Moscow to protest the criminal prosecution of the so-called Bolotnaya prisoners, with police detaining about 420 of the demonstrators, a spokesman for the Moscow branch of the Interior Ministry said, Interfax reported Monday.
In St. Petersburg, another 100 people gathered for a similar rally, and about 60 were detained, a spokesman for the local Interior Ministry branch said.
Amnesty International called the arrests "arbitrary" and said that the detention of most of the participants in Monday's peaceful rallies signaled that "the Russian authorities' rampant violation of freedom of expression and assembly shows no sign of letting up."
The sweep of arrests took place against the backdrop of the recent anti-government protests in Ukraine, where hundreds of thousands of people had rallied in the center of the capital for months, before the political crisis turned violent. More than 80 people were killed in Ukraine's street clashes, which culminated in the ouster of the country's president last weekend.
Moscow has harshly criticized the Ukrainian government for dithering in suppressing the protests, which it described as "terrorist" acts and mutiny.
In Russia, people took to the streets in May, 2012, to protest President Vladimir Putin's move to take office for a third term, which began the same month.
Amid clashes between the police and demonstrators in Moscow's Bolotnaya Ploshchad, more than 400 rally participants were detained, and a court on Monday handed down prison sentences ranging from 2 1/2 to four years in prison to seven people convicted of participating in the "riots."
Supporters of the Bolotnaya defendants rallied outside the courthouse and other locations to protest the trial, prompting police action to quash the expressions of discontent.
"Just a day after Russia was feted on the world stage at the closing ceremonies of the Sochi Winter Olympics, the Russian authorities have laid bare the reality of life in the country today," Amnesty International's head of Europe and Central Asia programs John Dalhuisen said in a statement.
"Those who dare to express dissenting views face serious consequences," he said.
The hundreds of people arrested on Monday "will be brought to account in accordance with law," an Interior Ministry spokesperson said.