Flower tributes were laid on the pavement where Boris Nemtsov, a charismatic former deputy prime minister turned Russian opposition leader, was shot and killed in central Moscow late on Friday night.
His was killed hours after making a public appeal to support a march in Moscow against the war in Ukraine that was to take place on Sunday.
Police say an unidentified attacker in a car shot Nemtsov four times in the back as he crossed a street just outside the Kremlin.
Nemtsov was a vocal critic of Russian President Valdimir Putin for plunging the country into a crisis with his policy over Ukraine.
Here is the late Boris Nemtsov speaking on the need for political reform in Russia.
"The country needs a political reform. When power is concentrated in the hands of one person and this person rules forever, this will lead to an absolute catastrophe, absolute. The current crisis is man-made. I will not hide the fact that the opposition is under strong pressure. Lies are being spread about the people, and one has to be a very strong person to cope with all this. I know this from my own experience. I have feelings too, so when I'm called different names, like a member of the fifth column (of traitors) and so on, it is very hard to live with this, but we should try to endure it."
The Kremlin says that Putin will personally oversee the investigations into the killing.
