MOSCOW, May 6 (RAPSI) - Opposition leaders have been granted permission to hold a rally for freedom in central Moscow on May 6, up to 30,000 participants are expected to show up.

The event will mark the anniversary of the protest rally on May 6 2012 in Moscow's Bolotnaya Square, when around 400 protesters were arrested as a result of severe riots which broke out. Dozens were injured, including a number of policemen.

An investigation has been launched against some 30 individuals in connection with the violence. Some of them were charged with inciting the riots. Almost 1,300 people were interrogated in the case.

Vyacheslav Aristov was among those who were detained. He has filed a claim against Russia with the European Court of Human Rights (ECHR) demanding 6,000 euro in compensation for damages arising from his arrest and sentencing for his involvement in the mass riots which tore through central Moscow on the eve of President Vladimir Putin's inauguration. He claims that his freedom to protest and his right to a fair trial were violated, and also that he was arrested unlawfully.

Konstantin Lebedev was among those involved in the rally last year. He was sentenced in April to 2.5 years in prison for organizing mass riots. During the hearings in the Moscow City Court Givi Targamadze, a Georgian politician, was named to be an alleged sponsor of the riots.

This year's rally is in aid of freedom and the participants will be calling for the release of those arrested last year. "We will be demonstrating for freedom of expression and the right to participate in fair and independent elections, and will be condemning arbitrary judicial and investigative action and unlawful prosecution," one of the rally organizers, Pyotr Tsarkov, told RIA Novosti on Monday.

Many well-known authors and actors are expected to speak at the rally, as well as opposition activists Alexei Navalny, Boris Nemtsov, Gennady Gudkov, and relatives and representatives of the jailed activists.

The police have reminded the organizers that law and order should not be violated.