Russian opposition leader Alexei Navalny was sentenced to 30 days in jail by a Moscow court on Tuesday for his role in organising nation-wide protests against President Vladimir Putin on May 5.

Some 1,600 anti-Kremlin activists, including Navalny, were detained during protests held ahead of Putin's inauguration for a fourth term as president.

Navalny had called for demonstrations in more than 90 towns and cities under the slogan "Putin is not our tsar" to protest what he says is Putin's autocratic rule.

Putin, 65, won re-election overwhelmingly in March, extending his grip over Russia for six more years - a tenure of 24 years that would make him Moscow's longest-serving leader since Soviet dictator Josef Stalin.

Navalny, who has been detained and jailed several times for organising similar protests, was barred from running in Russia's presidential election for what he says was a false pretext.

The court on Tuesday said Navalny's 30-day sentence would come into effect immediately, a Reuters correspondent there reported. The court then launched into a second trial on a separate charge - refusing to comply with a police order - which carries a maximum sentence of 15 days.