Thousands of people march for the third week in support of the arrested governor, Sergei Furgalo, Reuters writes.
The detention of the former governor, his supporters say, was politically motivated and has triggered more than two weeks of street protests.
The protesters oppose the Kremlin and demand release of Sergei Furgalo.
City authorities estimated around 6,500 people had taken part. Local media put the number at up to 20,000 people.
Sergei Furgalo was arrested on June 9. He is accused of organizing the murder of two people in business and threatening the life of one entrepreneur in 2004-2005. If justified, Furgalo is facing a life-sentence charge.
