Moscow, Aug 25 (IANS): Jailed Kremlin critic Alexei Navalny said that he has been moved to an isolation cell in the penal colony where he is being held, blaming Russian authorities for the step.

In a statement on Twitter on Wednesday, he said the authorities justified the move by saying he had failed to keep his hands behind his back for three seconds during a walk through the camp, dpa news agency reported.

"The directive obviously came from Moscow. Even by the standards of a Russian prison, sending one to the punishment cell just for three seconds without hands behind their back is too much," he tweeted.

His plan to establish a trade union from within the prison also angered the authorities recently.

Navalny said he had already spent three days in the cell, measuring 2.5 by 3 metres, last week allegedly because he had failed to button an item of clothing.

He tweeted: "Here I sit once again in my hellish closet with a mug and a book. It's kind of boring, of course. I think I need to learn how to meditate."

He is currently serving a sentence allegedly for fraud but widely seen as an attempt to silence one of the Kremlin's most vocal opponents.

He is being held in Penal Colony 6 in Melekhovo about 260 km north-east of Moscow, under particularly harsh conditions.

The Russian judiciary is widely seen as controlled by the Kremlin, and has been slammed for its arbitrary rulings by human rights activists.

Navalny narrowly survived an attempt to poison him with the chemical agent Novichok in August 2020, for which he blames President Vladimir Putin.