MOSCOW (AP) — Imprisoned Russian opposition leader Alexei Navalny has been transferred to a one-man cell, according to a post Thursday on his social media account.

Navalny was placed in solitary confinement, also called a “punishment cell,” on Nov. 1 but could only be held there for 15 days, according to the post on his Instagram account.

He said his new confinement is “a regular cramped cell, like the punishment cell, except that you can have not one but two books and use the prison kiosk, albeit on a very limited budget.”

The 46-year-old Navalny, Russian President Vladimir Putin’s most prominent foe, is serving a nine-year sentence in a maximum-security prison 250 kilometers (150 miles) east of Moscow.

He was arrested in January 2021 upon returning from Germany, where he had been recuperating from nerve-agent poisoning he blames on the Kremlin. He was given a two-and-half-year sentence for a parole violation and this year was sentenced to nine years for fraud and contempt of court.

He rejects the charges as politically motivated — a stance backed by Western nations — and an attempt by Russian authorities to keep him behind bars and out of politics for as long as possible.

Prior to his latest prison sentence, Navalny was the driving force behind an anti-corruption site that exposed alleged wrongdoing by high-ranking Russian officials.

The Associated Press