Russian opposition leader Alexei Navalny was sentenced to 15 days in jail by a Moscow court on Monday, following his call for a wave of anti-corruption protests the previous day.Navalny was one of hundreds of people detained at the Moscow rally on Sunday and spent the night in police custody. An estimated 8,000 people took to the streets of the Russian capital over allegations that Prime Minister Dmitry Medvedev was involved in a multi-billion dollar corruption scheme.Navalny was also fined 20,000 rubles ($352) for holding an unauthorised protest.