MOSCOW (AFP) - Top Russian opposition leader Alexei Navalny told hundreds of cheering supporters on Saturday that he would push ahead with his bid to become Moscow mayor after his surprise release from jail pending an appeal of an embezzlement conviction.

"We are going to run and we will win," Mr Navalny said through a loudspeaker after arriving in Moscow by train from the north-eastern city of Kirov, where a court on Thursday sentenced him to five years in a penal colony.

In a shock move, a higher court in the city released him from custody the following day pending his appeal of the conviction.