Jailed Russian opposition activist Vladimir Kara-Murza, who is serving a 25-year sentence for treason and fake news about the war in Ukraine, has been transferred to a new penal colony and placed in a solitary confinement cell, the independent news outlet Novaya Gazeta reported Tuesday, citing his lawyer.The news comes just a day after Kara-Murzas family said he had been moved from the IK-6 maximum-security penal colony in the Omsk region, some 2,700 kilometers east of Moscow, and sent to an unknown location.On Friday, without any warning, I was called to the commission for another malicious violation when I did not get up at the command rise, the jailed activist was quoted as having written to his lawyer.They decided to transfer me to [a solitary confinement cell], so that life doesnt seem all sunshine and roses, he added.According to Kara-Murzas lawyer, he will remain in the solitary confinement cell at the new IK-7 penal colony in the Omsk region until May 26, but noted that this date could be changed.The independent Meduza news websitedescribed the type of confinement cell the activist was placed in as the most severe form of punishment available at a Russian prison.Kara-Murza, 42, was arrested in April 2022 after he criticized the Kremlins invasion of Ukraine.In April of last year, he wassentenced to 25 years in prison on charges of treason, false information about the Russian army and affiliation with an undesirable organization.His prison sentence is one of the longest to be handed down against an opposition figure in recent years.His lawyers and family have said his health has deteriorated in prison as he suffers from a nerve condition called polyneuropathy due to two near-fatal poisoning attempts in 2015 and 2017.