Navalny was one of 1,600 arrested during anti-Putin rallies across the countryThe Russian opposition leader Alexei Navalny was been released from police custody on Sunday after being detained during nationwide protests ahead of Vladimir Putin ’s inauguration for a fourth presidential term.Navalny, 41, was one of 1,600 people arrested by police aided by pro-Kremlin Cossack activists as Russians rallied in scores of towns and cities prior to Putin’s inauguration on Monday.“It appears the order ‘don’t jail until the inauguration’ came through,” said Navalny, who has been ordered to appear in court on Friday. The Kremlin critic faces up to 30 days in jail on charges of disobeying police and organising an illegal protest. He spent two months in jail last year after being detained at anti-Putin rallies.In Moscow , where over 700 protesters were arrested, human rights figures called for an investigation into why people claiming to be Cossacks were allowed to assist the police crackdown. Some used traditional Cossack leather whips to attack opposition supporters. “We’ll do over anyone who makes trouble against Putin,” an unidentified “Cossack” was reported as saying by the Meduza news website.Maxim Shevchenko, a member of the Kremlin’s human rights council, called for an urgent session of the council to discuss the use of force by Cossacks against protesters in Moscow and other cities. The opposition rallies came just six weeks before the World Cup kicks off in Russia.Denis Krivosheev, Amnesty International’s deputy director for eastern Europe and central Asia, accused Russian police of failing to act while “people in Cossack uniforms” beat protesters.The Kremlin has in recent years encouraged a revival of the Cossacks, the descendants of the fiery Tsarist-era horsemen who once guarded Russia’s southern borders.Cossacks have acted as an auxiliary police force in some cities, regularly undertaking street patrols on the lookout for illegal immigrants. They have also taken part in raids on art galleries and theatres deemed to have displayed “blasphemous” material. Cossack paramilitary groups have fought alongside Russian-led separatists in eastern Ukraine.They have also targeted Kremlin critics. In 2016, a group of Cossacks attacked Navalny and his supporters in Anapa, a city in southern Russia. Members of Pussy Riot, the anti-Kremlin performance art group, were set on by Cossacks ahead of the 2014 Winter Olympics in Sochi. No charges were brought against the assailants in either case.Hundreds of members of the Kremlin-backed Molodaya Gvardia youth movement also helped police make arrests at Saturday’s rally in Moscow, while activists from the pro-Putin National Liberation Movement were involved in scuffles with protesters.