Kremlin critic Alexei Navalny on Monday urged Russians to take to the streets in protest after a judge remanded him in pre-trial detention for 30 days despite calls from Western countries to free the opposition politician.

The United Nations and Western countries had told Moscow before the ruling to let Navalny go, and some countries have called for new sanctions on Moscow, which on Monday told them to mind their own business.

The ruling to remand him in custody for violating the terms of a suspended jail sentence, a day after he flew back to Russia for the first time since he was poisoned with a nerve agent last summer, could be the prelude to him being jailed for years.