Mourners shout in defiance at funeral for Alexei Navalny

Hundreds of people in Russia have gathered for the funeral service of Alexei Navalny, the vocal Putin critic who died in jail last month.

Despite a large police presence and barricades set up in the area, mourners burst into applause as his body was taken into a church outside Moscow on Friday morning.

"You weren't afraid, and neither are we!", they shouted.

Those in attendance risk arrest for showing support for Navalny.

His wife has blamed President Vladimir Putin for his death, but Moscow says he died of natural causes.

The opposition leader died on 16 February in a Russian prison in the Arctic Circle. He had been jailed for three years on trumped-up charges.

The memorial service began just after 14:00 Moscow time (11:00 GMT) at the Church of the Icon of Our Lady Quench My Sorrows, in Maryino.

Among those pictured near the church ahead of the funeral service were foreign dignitaries, including the US, German and French ambassadors.

The burial will take place at the nearby Borisovskoye Cemetery at 16:00.

Scenes from the area around the church are being streamed online on Navalny's YouTube channel. His team have complained of disruption to mobile phone signals - and no filming was allowed inside the church itself.

Scores of mourners were arrested as they gathered to pay tribute to the Russian opposition figure in the immediate aftermath of his death.

And as many ignored those fears on Friday, Kremlin spokesman Dmitry Peskov warned that "any unauthorised gatherings will be in violation of the law, and those who participate in them will be held accountable".

Undeterred, one mourner told Reuters news agency: "I came because this is the only opportunity for me to say goodbye to Alexei. I admire his courage, I admire his resilience."

"Why he is feared even dead, I don't understand. That's why I'm here," they added.

"What are they afraid of? Why so many cars?" said another, Anna Stepanova, in reference to the barriers and the anti-riot police trucks.

"They are so afraid themselves," she told AFP news agency. "The people who came here, they are not scared. Alexei wasn't either."

Hours before the ceremony, Navalny's spokeswoman Kira Yarmysh said they were having difficulties with arrangements.

The team were even finding it difficult to find a hearse, she said.

The opposition leader's team - who are overseas and have encouraged people to attend - had shared a map of the route between the two locations.

They also shared a list of places abroad - from Seoul to Rome, Montreal and Stockholm - where people can join memorial services.

In March 2015, thousands lined the streets to pay homage to slain opposition politician Boris Nemtsov, but it was always unlikely any similar public outpouring of grief for an opponent of President Putin would be allowed now.

In recent years, Russian authorities have cracked down on any action that could be interpreted as criticism of the government. Attempts at commemorating Navalny's death were met by a heavy-handed response, with makeshift monuments cleared and hundreds arrested.

Telegram channel RusNews also said that surveillance cameras had been installed "on every streetlight" surrounding the cemetery.

First Department - a group of lawyers and human rights defenders - has shared advice on social media for those planning to go to Navalny's funeral.

It warned about "pro-government activists" acting as provocateurs and urged people to remain vigilant: "Detentions cannot be ruled out after the ceremony... Stay under the radar of security forces - do not use public transport or apply for paperwork in the days after the funeral."

The advice also includes not carrying any objects bearing the photograph of Navalny or the symbol of his Anti-Corruption Foundation, which was declared an extremist organisation by Russian authorities.

Navalny's mother and father were seen going into the church. Navalny's children Daria, 23, and Zakhar, 15, live abroad.

His widow, Yulia, has also been overseas recently and might be at risk of being arrested if she returns.