Boris Nemtsov: Russians march in memory of slain Putin opponent
Thousands of people have taken to the streets of Russia's capital to mark five years since the murder of opposition leader Boris Nemtsov.
Mr Nemtsov, a former deputy prime minister and prominent Kremlin critic, was shot dead in 2015.
Participants on Saturday also used the march to protest against controversial plans to change the constitution.
Opponents say President Vladimir Putin wants to make the changes to retain power after his term ends in 2024.
- Nemtsov: A charismatic figure and fierce Putin critic
- Prague denies renaming square to troll Moscow
- What is Russia's Putin up to?
Organisers said linking the annual commemorative march with a protest against constitutional reform was what Mr Nemtsov would have wanted.
"This is exactly what Boris Nemtsov was fighting for, and he gave his life for it," they wrote on the event's web page.
What happened at the protest?
Police said about 10,000 people took part in the Moscow march, while monitoring organisation White Counter estimated there were more than 22,000 participants.
Those taking part carried photos of Mr Nemtsov and signs bearing anti-Putin messages, such as "No to eternal Putin" and "No to the usurpation of power".
Energy worker Sergei Tsaplienko told Reuters news agency he was joining the march because he wanted freedom and democracy.
"I haven't got the strength to stand the government's abuses of power," he said. "The constitution is about to be transformed into some sort of comic strip."
Mr Putin proposed an overhaul of the constitution - including a slight redistribution of powers between branches of the government - in January.
He said the changes would make the constitution more democratic and more effective, but the proposals have been widely seen as a way of allowing him to extend his grip on power after leaving the presidency.
The changes will be put to a national vote in April.
Demonstrators on Saturday also called for authorities to find and prosecute those who orchestrated the killing of Mr Nemtsov.
Who was Boris Nemtsov?
Mr Nemtsov rose to political prominence in the 1990s as a liberal reformer and deputy prime minister under President Boris Yeltsin.
His political fortunes waned when Mr Putin took over the presidency, but he became an important opposition force as anti-Putin protests erupted in 2011.
He was openly critical of Russia's involvement in eastern Ukraine after the annexation of Crimea in 2014. On the night before his death, he took part in a radio interview in which he backed a protest march.
Mr Nemtsov's allies accused the Kremlin of involvement in his murder. Putin condemned the murder as "vile" and vowed to find the killers.
Five Chechen men were convicted over Mr Nemtsov's killing, but family and supporters of the slain politician believe the person who ordered the murder remains at large.
Demonstrations in his memory also took place on Saturday in other cities in Russia, including St Petersburg.