Thousands of Russians marched through Moscow on Sunday shouting slogans such as "Russia will be free!" and "Putin is war!" to mark two years since opposition leader Boris Nemtsov was gunned down outside the Kremlin.
Nemtsov, a former deputy prime minister, was a fierce critic of President Vladimir Putin. His Feb. 27, 2015, death, in what appeared to be a contract killing, sparked an outpouring of anger and fear in Russia's beleaguered opposition movement.
The memorial protest was the largest opposition gathering since a similar march for Nemtsov in 2016. Organizers put the number of participants at just over 15,000. The police, known for underestimating attendance at political rallies, said about 5,000 people showed up.
"It's very important that after two years people continue to come out and show their solidarity with the ideas for which Boris Nemtsov fought for and gave his life," opposition activist Ilya Yashin, who was Nemtsov's friend and colleague, told the Interfax news agency.
Demonstrators carried Russian flags, banners of opposition political parties and placards with quotes from Nemtsov, including "If there's Putin, there's no Russia," and "Our only chance left is the street." Some carried cardboard Russian flags with bullet holes in them.
"For us, Nemtsov represents free-thinking Russia and the democratic values for which we strive: free elections and no corruption," participant Yekaterina Getgarts said.
Five men went on trial for Nemtsov's murder in a Moscow military court last year, but no verdicts have been returned in the ongoing case. Investigators allege that the man who shot Nemtsov was Zaur Dadayev, a former officer in an elite Chechen police unit. .
But Nemtsov's family and friends say it was a political hit with a trail that leads to senior officials in the North Caucasus republic of Chechnya who have not been charged or even questioned.
The Moscow rally largely passed without incident, but an unknown assailant threw green dye in the face of opposition leader Mikhail Kasyanov. Police made several arrests
"This is the hysteria of the government. They do not know what to do. The government is afraid," opposition activist Gennady Gudkov, a former deputy in the lower house of parliament, said of the attack on Kasyanov.
While large crowds are rare at opposition demonstrations in Putin's Russia, the attendance at Sunday's rally was significantly lower than a year ago, when organizers estimated almost 25,000 people joined a Nemtsov memorial march.
Russia's opposition has been fragmented in recent years by pressure from the Kremlin, the flight abroad of leading activists and political infighting.
After the march, thousands of people laid flowers on the bridge where Nemtsov was shot in the back several times while walking home with his girlfriend.
Similar demonstrations took place Sunday in other Russian cities, including St. Petersburg and Nemtsov's hometown of Nizhny Novgorod. Several thousand people participated in St. Petersburg, but the turnout was low elsewhere.