Jailed Kremlin critic Alexei Navalny has been transferred to a strict-regime penal colony, his allies said on Tuesday, expressing concern about his safety.
Navalny had been serving two-and-a-half years in a prison around 100 kilometres (60 miles) east of Moscow for violating parole on old fraud charges in what his allies say is punishment for challenging the Kremlin.
In March, the 46-year-old had his jail time extended to nine years after he was found guilty of embezzling donations to his political organisations and contempt of court.
On Tuesday, one of Navalny's lawyers, Olga Mikhailova, said officials at his penal colony reported he had been transferred to a strict-regime colony.
One of his close allies, Maria Pevchikh, tweeted that Navalny did not show up for the meeting with his lawyers. "We have no further information on where Navalny is being taken," she added.
Although the Russian authorities did not disclose the location of the new penal colony, it is thought to have harsher conditions than his current prison in the town of Pokrov.
"The problem with his transfer to another colony is not only that the high-security colony is much scarier," Navalny's spokeswoman Kira Yarmysh said on Twitter.
"As long as we don't know where Alexei is, he remains one-on-one with the system that has already tried to kill him, so our main task now is to locate him as soon as possible," she added.
She said that neither Navalny's family nor his lawyer were notified in advance of the transfer.
The United States called on Russia to grant Navalny access to his lawyers and medical care and condemned the "politically motivated" actions against him.
Russian authorities "will be held accountable by the international community for anything to befall Mr Navalny," State Department spokesman Ned Price told reporters in Washington.
"We reiterate our call for his immediate release as well as an end to the persecution of his many supporters," Price said.
Navalny rose to prominence as an anti-corruption blogger and, before his imprisonment, mobilised anti-government protests across Russia.
In 2020, he barely survived a poisoning attack with Novichok, a Soviet-designed military-grade nerve agent. Navalny has accused Russian authorities, but the Kremlin has denied any involvement.
He was arrested last year on his return from treatment in Germany, sparking widespread condemnation abroad and sanctions from Western capitals.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
Track Latest News Live on NDTV.com and get news updates from India and around the world