Alexei Navalny, the fiercest foe of Russian President Vladimir Putin who crusaded against official corruption and staged massive anti-Kremlin protests, died in prison on Friday, Russia’s prison agency said.
Mr Navalny was 47.
The news, less than a month before an election that will give Mr Putin another six years in power, brought renewed criticism and outrage from world leaders toward the Russian president who has suppressed opposition at home.
After initially allowing people to lay flowers at monuments to victims of Soviet-era repressions in several Russian cities, police sealed off some of the areas and started making arrests.
More than 100 people were detained in eight cities, including Moscow, St. Petersburg, Murmansk in the Arctic Circle, Krasnodar and Rostov-on-Don in the south of Russia, according to the OVD-Info monitoring group.
Shouts of “Shame!” were heard as Moscow police rounded up more than a dozen people — including one with a sign reading “Killer” — near a memorial to political prisoners, the group said.
The federal prison service said in a statement that Mr Navalny felt unwell after a walk on Friday and lost consciousness.
An ambulance arrived to try to rehabilitate him, but he died.
Kremlin spokesman Dmitry Peskov says Mr Putin was informed of the death and the prison service was looking into the circumstances in line with standard procedures.
Mr Navalny’s spokeswoman, Kira Yarmysh said on X, formerly Twitter, that the politician’s team had no confirmation of his death so far and that his lawyer was travelling to the town where he was held.
Just hours after his death was reported, Mr Navalny’s wife, Yulia Navalnaya, took the stage at a security conference in Germany where many world leaders had gathered.
She said she had considered cancelling her appearance.
“But then I thought what Alexei would do in my place. And I’m sure he would be here,” she said, while noting that she was not even sure if she could believe the news coming from official Russian sources.
“But if this is true, I want Putin and everyone around Putin, Putin’s friends, his government to know that they will bear responsibility for what they did to our country, to my family and to my husband. And this day will come very soon.”
Mr Navalny, who was serving a 19-year sentence on charges of extremism, was moved in December from his former prison in the Vladimir region of central Russia to a “special regime” penal colony – the highest security level of prisons in Russia – above the Arctic Circle.
His allies decried the transfer to a colony in the town of Kharp, in the Yamalo-Nenets region about 1,200 miles north-east of Moscow, as yet another attempt to force Mr Navalny into silence.
The remote region is notorious for long and severe winters.
Kharp is about 60 miles from Vorkuta, whose coal mines were part of the Soviet gulag prison camp system.
Mr Navalny had been behind bars since January 2021, when he returned to Moscow after recuperating in Germany from nerve agent poisoning that he blamed on the Kremlin.
Before his arrest, he campaigned against official corruption, organised major anti-Kremlin protests and ran for public office.
He had since received three prison sentences, all of which he rejected as politically motivated.
He was convicted in 2013 of embezzlement on what he called a politically motivated prosecution and was sentenced to five years in prison, but the prosecutor’s office later surprisingly demanded his release pending appeal. A higher court later gave him a suspended sentence.
The day before the sentence, Mr Navalny had registered as a candidate for Moscow mayor. The opposition saw his release as the result of large protests in the capital of his sentence, but many observers attributed it to a desire by authorities to add a tinge of legitimacy to the mayoral election.
Mr Navalny finished second, an impressive performance against the incumbent who had the backing of Mr Putin’s political machine and was popular for improving the capital’s infrastructure and aesthetics.
Mr Navalny’s popularity increased after the leading charismatic politician, Boris Nemtsov, was shot and killed in 2015 on a bridge near the Kremlin.
Whenever Mr Putin spoke about Mr Navalny, he made it a point never to mention the activist by name, referring to him as “that person” or similar wording, in an apparent effort to diminish his importance.