Russia's Federal Security Service said on Tuesday it had opened a criminal case against exiled Kremlin critic Mikhail Khodorkovsky, accusing him of creating a "terrorist organization" and of plotting to violently seize power.

Khodorkovsky, an oil tycoon who was once Russia's richest man, served 10 years in a Siberian prison on fraud charges that he and many Western countries said were politically motivated.

The Federal Security Service said the charges relate to the activities of a Khodorkovsky-backed group that opposes the war in Ukraine. The group, called the Anti-War Committee, has been banned in Russia.

There was no immediate comment from Khodorkovsky or his representatives.

Backed Yeltsin in 90s

Khodorkovsky rose to prominence as one of a handful of wealthy businessmen who back

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