Navalny’s supporters in Moscow plan to rally near the Kremlin administration and the headquarters of the FSB Police have said the protests have not been authorized and will be broken up, as they were last weekend MOSCOW: Police detained more than 4,400 people across Russia and blocked off the centre of Moscow on Sunday in a massive clampdown on protests demanding the release of jailed Kremlin critic Alexei Navalny. Thousands of protesters defied government warnings to rally from Vladivostok to Saint Petersburg in a second weekend of mass demonstrations over the arrest of President Vladimir Putin"s most prominent opponent. Navalny was detained at a Moscow airport in mid-January after flying back to Russia from Germany where he was recovering from an August poisoning he blames on the Kremlin. The 44-year-old anti-corruption campaigner is being held in a Moscow detention centre and faces years of potential jail time in several different criminal cases, despite calls from Western governments for his release. In moves not seen in years in Moscow, authorities locked down the centre of the capital Sunday, with hundreds of police lining the streets, central Metro stations closed and the movements of pedestrians restricted. Protesters who had hoped to gather outside the headquarters of the FSB security service were instead scattered to various parts of the city as organisers made last-minute changes in locations. AFP journalists saw dozens of protesters detained and taken into police vans. MORE THAN 4,000 DETAINED Several thousand were seen marching throughout the city centre, but it was unclear amid the chaos how many people took part in the demonstration. Independent monitor OVD-Info said at least 4,407 people had been detained across the country, after reporting more than 4,000 detentions during similar protests on January 23. It said at least 1,365 were detained in Moscow and 962 in Saint Petersburg, as well as 82 journalists across the country. US Secretary of State Antony Blinken on Twitter condemned "the persistent use of harsh tactics against peaceful protesters and journalists by Russian authorities for a second week straight." The Russian foreign ministry hit back, accusing the United States of "gross interference" in its affairs and of using "online platforms controlled by Washington" to promote the protests. Protesters chanted "Freedom!" and "Putin is a thief!" as they marched through Moscow, braving bitter cold and snow. Several hundred protesters eventually gathered outside the Matrosskaya Tishina prison where Navalny is being held. Dozens were detained outside the complex. "It"s almost embarrassing that the state is so afraid of us," 31-year-old protester Elisaveta Dementieva told AFP at the Moscow demonstration. Many protesters carried gold-painted toilet brushes in reference to a video released by Navalny"s team alleging that Putin had been gifted a $1.35 billion property on the Black Sea coast, which among other luxurious goods featured toilet brushes costing 700 euros ($840) apiece. As night fell in Moscow protesters began to head home, with some wondering whether the demonstration would have any impact. "It"s true we are asking ourselves if these protests will really do any good," said Nadia, a 21-year-old student. "It will take more for Navalny to be freed. And even more for Russia to be free." Several thousand people demonstrated in the second city of Saint Petersburg, despite police closing off the main thoroughfare Nevsky Prospekt and shutting Metro stations, an AFP journalist reported. Police were seen roughly detaining several protesters, including one young man who was left with a bloodied head. Earlier, protesters had rallied in cities including the Pacific port of Vladivostok, where dozens escaped the police on the frozen waters of the Amur Bay and danced in a circle. Several thousand were also reported to have protested in the Siberian city of Novosibirsk despite temperatures dropping to -20 degrees Celsius (-4 degrees Fahrenheit). Russian authorities issued several warnings against participating in the unauthorised rallies and threatened criminal charges against protesters. The head of Russia"s Human Rights Council, Valery Fadeyev, called Sunday"s events a "provocation" and said they have "nothing to do with protecting rights", news agency TASS reported. Navalny is due in court several times next week, including on Tuesday on charges of violating the terms of a 2014 suspended sentence. His team has called for supporters to gather outside the courtroom. Navalny"s wife Yulia posted a picture of her family on Instagram on Sunday, urging supporters to make their voices heard. "If we remain silent, then tomorrow they will come for any one of us," she wrote. Navalny"s team said Yulia was detained by police shortly after she announced her arrival at Sunday"s rally on social media.