MOSCOW - A Moscow court on Monday gave a 30-day jail sentence to Russian opposition leader Alexei Navalny over an unsanctioned protest earlier this year, just days before another planned political rally.

Judge Alexei Stekliyev of the Tverskoy District Court in the capital ruled that Navalny had repeatedly violated Russian law with a call for a mass protest in January, an AFP correspondent in the courtroom reported. Navalny was detained on Saturday evening outside his home in Moscow. His charges pertain to an unsanctioned protest he organised on January 28, violating Russia's strict laws which forbid any public event without city hall's authorisation.

In the courtroom Monday, Navalny's defense lawyer asked the judge for two days in order to read through the case, which contains 219 pages, but Stekliev only allowed 30 minutes. Speaking before the decision, the 42-year-old Kremlin critic said the case was an indictment of Russia's political system.

"Over the past four years... Moscow has not once approved our request to rally where we requested," he said.

He added that the only reason he is being held on the same charge for the third time is to keep him from holding a protest on September 9 against the government's retirement age hike.

Navalny has called some of the biggest protests in Russia in recent years. His anti-corruption rhetoric is especially popular among younger people who follow his online channels and blogs.