Supporters of jailed Russian opposition leader Navalny mark his 47th birthday

Russian opposition leader Alexei Navalny makes a heart gesture standing in a cage during a hearing in Moscow, Russia (Moscow City Court via AP/PA)

Imprisoned opposition leader Alexei Navalny voiced hope for a better future in Russia as his supporters held pickets and demonstrations to mark his 47th birthday on Sunday.

Mr Navalny is serving a nine-year sentence for fraud and contempt of court, charges he says were trumped up to punish him for his work to expose official corruption and organising anti-Kremlin protests.