Thousands of people in Moscow and across Russia who took to the streets Sunday were met with the harshest show of force the country has seen in recent years. Protesters throughout the country had gathered for the second weekend in a row to support jailed opposition leader Alexey Navalny, who has been held by Russian authorities since mid-January. More than 5,000 people were detained in at least 85 cities as of late Sunday, according to the independent monitoring group OVD-Info -- a record since 2011. In Moscow, the capital, more than 1,600 people were arrested, including Navalny's wife Yulia, though she was later released. Navalny himself has been behind bars since shortly after he arrived in Moscow on January 17. The longtime Russian dissident had spent the previous several months in Germany where he was recovering from being poisoned with Novichok, a powerful nerve agent. Navalny accused the Russian government and President Vladimir Putin of trying to kill him, an allegation the Kremlin has repeatedly denied. A joint investigation last month by CNN and the investigative group Bellingcat implicated the FSB in Navalny's August poisoning, piecing together how an elite unit at the agency followed Navalny's team throughout a trip to Siberia, at the end of which Navalny fell ill from exposure to military-grade Novichok. Russia has denied involvement in the case. #FrederikPleitgen #CNNInternational #News