Flags and flowers Moscow city authorities had approved a march of up to 50,000 people there.

Tens of thousands of people have marched through central Moscow to honour opposition politician Boris Nemtsov, who was shot dead on Friday.

Flags and flowers

They carried portraits of Mr Nemtsov and banners saying "I am not afraid.

Mr Nemtsov's allies have accused the Kremlin of involvement, but President Vladimir Putin condemned the murder as "vile" and vowed to find the killers.

Opposition supporters gathered at a point not far from the Kremlin before marching past the spot on Great Moskvoretsky Bridge where Mr Nemtsov was killed. Some chanted "Russia without Putin!"

Several thousand people also marched in St Petersburg.

Flags and flowers

Moscow city authorities had approved a march of up to 50,000 people there.

These placards read: "Heroes don't die" and "These bullets are for each one of us"

There is a heavy police presence, including at the scene of the killing

The attendance has yet to be confirmed but runs into the tens of thousands

There has been no official figure on turnout yet, with estimates ranging from 16,000 to 70,000.

Many people carried the national flag and flowers to lay at the scene of the killing, which was already piled with tributes. A few were holding Ukrainian flags.

Some of the placards read: "He died for the future of Russia" and "They were afraid of you, Boris".

Maria Glazacheva, a 22-year-old student in Moscow who joined the march, told the BBC: "Boris was a good and honest man. Moscow is a sad place today."

Opposition politician Ilya Yashin told Associated Press the killing was "a political murder aimed at frightening the... part of the population that supported Nemtsov and did not agree with the government. I hope we won't get scared".

Another opposition figure, Gennady Gudkov, told Reuters: "If we can stop the campaign of hate that's being directed at the opposition, then we have a chance to change Russia. If not, then we face the prospect of mass civil conflict."

Pro-Kremlin activists from the group Anti-Maidan had said they would not disrupt the march.