MOSCOW (AP) Chanting slogans against President Vladimir Putin, tens of thousands took to the streets Sunday across Russia to demand the release of jailed opposition leader Alexei Navalny, keeping up nationwide protests that have rattled the Kremlin. More than 4,700 people were detained by police, according to a monitoring group, and some were beaten.

Russian authorities mounted a massive effort to stem the tide of demonstrations after tens of thousands rallied across the country last weekend in the largest, most widespread show of discontent that Russia had seen in years. Despite threats of jail terms, warnings to social media groups and tight police cordons, the protests again engulfed cities across Russias 11 time zones on Sunday.

Navalnys team quickly called another protest in Moscow on Tuesday, when he is set to face a court hearing that could send him to prison for years.

The 44-year-old Navalny, an anti-corruption investigator who is Putins best-known critic, was arrested on Jan.17 upon returning from Germany, where he spent five months recovering from nerve-agent poisoning that he blames on the Kremlin. Russian authorities have rejected the accusations. He was arrested for allegedly violating his parole conditions by not reporting for meetings with law enforcement when he was recuperating in Germany.