Several thousand people have begun a march in Moscow in memory of Russian opposition leader Boris Nemtsov to mark the first anniversary of his killing.

Nemtsov was shot to death late at night as he and a companion walked across a bridge overlooking the Kremlin. The brutality so close to the centre of Russian power both frightened and angered supporters of the beleaguered opposition.

Nemtsov, who had been a prime minister during Boris Yeltsin's presidency, was a charismatic figure and a vehement critic of President Vladimir Putin.

"He was the embodiment of freedom and courage, he was a model for me," said marcher Kamala Igamberdiyeva, a 26-year-old accountant. "We still have a chance if the opposition shows wisdom and unites."

In Putin's decade-and-a-half in power, opposition groups have come under severe pressure, criticized by officials and state-controlled media as pawns of the West. Permission for rallies is frequently denied.

Many opposition supporters say that even if Putin had no direct hand in Nemtsov's killing, he bears responsibility for encouraging a truculent authoritarianism.

"Nemtsov's death was the result of the atmosphere of hatred in our country," said 78-year-old demonstrator Pavel Movshovich.

Other protestors echoed this feeling of disillusionment with their country, FRANCE 24’s Thomas Lowe reported from Moscow.

“One man told me that Russia is, quite simply, a country where democracy has ceased to exist,” Lowe said. “So this march is a memorial march, but for a lot of people here the point is to show support for an opposition that has tried to gather itself together in view of the parliamentary elections that are coming up in September.”

Five suspects have been arrested in the killing, all of them Chechens. The suspected triggerman served as an officer in the security forces of the Moscow-backed Chechen leader, Ramzan Kadyrov.

“However, the family has said that they aren’t happy with the way that justice is being carried out because they think that the person who gave the order to murder Boris Nemtsov, quite simply, will never be found,” Lowe reported.

Five suspects have been arrested in the killing, all of them Chechens. The suspected triggerman served as an officer in the security forces of the Moscow-backed Chechen leader, Ramzan Kadyrov.

City authorities denied march organizers permission to hold a procession to the bridge, but gave permission for another route in central Moscow on Saturday.

On Saturday morning, US Ambassador John Tefft laid a wreath at the bridge, saying he came to express hope that "some of the dreams that Boris Nemtsov had will come true in Russia".

(FRANCE 24 with AP)