The police were on the scene outside the prison when Navalnyj walked out, but made no attempt to arrest him again. However, he risks being again deprived of liberty because he has continued to call for protests.

The opposition leader immediately condemned the Russian authorities' act of terrorism as they prevented protests in Moscow in recent weeks.

"The movement will continue to grow and the regime will regret what it has done," he told reporters outside the prison.

More arrested

The arrest and verdict came a few days before the protest he called for, which aimed to exclude several opposition politicians from a local election in September.

Several other prominent opposition politicians were arrested and their homes were searched on the same day as Navalnyj and more than 550 people were arrested during the demonstration day on July 27, in which around 3,500 people participated.

The protests were illegal, according to authorities.

During prison time, Navalnyj received hospital care for what, according to doctors, was a "serious allergic reaction". Navalnyj himself has said that he may have been poisoned.

20,000 in demonstration

The weekend before Navalnyj was arrested, according to the opposition, more than 20,000 people demonstrated together with the opposition politicians who refused to stand in the local elections.

Most opposition leaders who are not allowed to stand in the local elections have also been detained for violating demonstration laws.

Russian President Vladimir Putin spoke for the first time about the move on a visit to France on Monday. He then promised to prevent the mass demonstrations in Moscow, similar to the Yellow West protests in France.