Russian opposition leader Alexei Navalny said on Tuesday he would keep organising large anti-Kremlin demonstrations despite being jailed for 15 days after orchestrating the biggest protests against the authorities in years.

Navalny, who wants to run against Vladimir Putin for president next year, was speaking a day after being freed from jail and making his first public comments about the March 26 protests which resulted in over 1,000 arrests.

"I of course assess the March 26 action to be very successful," said Navalny, addressing his supporters in an online broadcast.

"It was the first simultaneous action in towns since the 1990s. Despite the fact that the authorities tried to frighten everyone ... tens of thousands took to the streets. We need to continue."

Putin, who has dominated Russia's political landscape for the last 17 years, has not yet said whether he will run for what would be a fourth presidential term next year but is widely expected to do so.

Opinion polls suggest Navalny has little chance of unseating the Russian leader, who enjoys high ratings. But Navalny and his supporters hope to use the Internet to channel public discontent over official corruption to get more support.