Russian opposition activist Alexei Navalny stands in a court room as he waits for a session in Moscow, Russia, Monday, Sept. 24, 2018. Navalny was released from jail on Monday at the end of a 30-day sentence... (Associated Press) 
 
 Russian opposition activist Alexei Navalny stands in a court room as he waits for a session in Moscow, Russia, Monday, Sept. 24, 2018. Navalny was released from jail on Monday at the end of a 30-day sentence for staging an unsanctioned protest — and then immediately detained again on staging another... (Associated Press) 
 
 MOSCOW (AP) — Immediately after being released from jail at the end of a 30-day sentence, Russian opposition leader Alexei Navalny was detained again on Monday and ordered to spend 20 more days behind bars. 
 
 Navalny, President Vladimir Putin's most visible opponent, has served numerous jail sentences for spearheading a series of unsanctioned protests across Russia. 
 
 Just as he walked out of a detention center in Moscow for organizing an unauthorized rally earlier this year, a police officer took him away. 
 
 The Simonovsky District Court later sentenced him to 20 days in custody on charges of staging another rally earlier this month that caused bodily harm to police officers and damaged a patrol vehicle. Navalny denied the allegation, saying that as he was serving the 30-day jail sentence he couldn't have organized the unsanctioned rally. 
 
 Navalny's further detention comes amid a wave of popular discontent against an increase in the retirement age, an issue that angered Russians across the political spectrum. 
 
 A drop in approval ratings for Putin and outrage at the changes in the pension system have weighed heavily on Kremlin candidates running in regional elections in Russian regions. 
 
 Early results from runoff votes in Sunday's gubernatorial elections in two Russian regions see opposition candidates beating Kremlin incumbents. 
 
 A week earlier, an opposition candidate for governor in the Far East mounted protests following widespread reports of vote-rigging in favor of the Kremlin candidate. Several days later, election authorities canceled the results of the elections and called a new vote. 

 Image copyright AFP/Getty Images Image caption Alexei Navalny (right) is expected to appear in a Moscow court later on Monday 
 
 Russia's opposition leader Alexei Navalny has been detained again - moments after he had finished serving a 30-day sentence, his colleagues say. 
 
 He is accused of violating a protest law and was sentenced to another 20 days in jail. 
 
 The sentence Mr Navalny had just served was over planning an unauthorised anti-government demonstration in January. 
 
 The 42-year-old politician has long been the most prominent face of Russian opposition to President Vladimir Putin. 
 
 Mr Navalny and his supporters believe the pressure he is coming under is politically motivated, the BBC's Steven Rosenberg in Moscow reports. 
 
 In recent weeks, the opposition politician has called for nationwide protests against government plans to raise the retirement age in Russia - a deeply unpopular reform that is fuelling resentment with the authorities and which has dented Mr Putin's popularity, our correspondent says. 
 
 Media playback is unsupported on your device Media caption How the Russian state uses surveillance and propaganda to discredit opponents 
 
 Earlier this month, the head of Russia's National Guard Viktor Zolotov had threatened to make "a juicy beefsteak" out of Alexei Navalny, after the political activist had published allegations of large-scale corruption within the National Guard. 
 
 Mr Navalny has called Mr Putin's party a place of "crooks and thieves", accused the president's system of "sucking the blood out of Russia" and vowed to destroy the "feudal state" being built. 
 
 The Kremlin denies the allegations. 
 
 Mr Navalny's candidacy in the 2018 presidential election was banned by the authorities over his conviction by a Russian court of embezzlement, which barred him from running for office.
– President Vladimir Putin's most visible critic was released from a Russian jail on Monday only to be immediately arrested again and thrown back in. Alexei Navalny served a 30-day sentence on charges he staged an unsanctioned protest before being re-arrested on charges he staged a rally that caused bodily harm to police officers, per the AP. Navalny, who has long been the face of Russian opposition to the Putin regime, denied the allegations and argued he couldn't have organized the rally in question because he was in a Moscow jail serving out the 30-day sentence when it happened. Per the BBC, the 42-year-old opposition leader and his allies have said they believe the arrest was politically motivated. It also comes at a time of political unrest in Russia, sparked in part by an increase in the country's retirement age. Putin's own approval ratings have dropped amid the outrage and observers say the issue has become a noose around the necks of Putin-alligned candidates running for regional offices. It's a wave of discontent that Navalny and his allies have harnessed as they organize anti-government demonstrations in cities across the vast country. Navalny's prominence has frequently put him in the Kremlin's crosshairs. Just this month, Putin's chief of the National Guard challenged Navalny to a duel and threatened to "make a good juicy beef steak" of the opposition leader.