MOSCOW (AP) — Thousands of demonstrators rallied Saturday in the Russian Far East city of Khabarovsk to protest the arrest of the regional governor. The demonstrations are part of a three-week wave of opposition that has challenged the Kremlin. Smaller demonstrations took place in at least 10 other cities, leading to 55 people being detained, according to an agency that monitors protests. No detentions were reported at the Khabarovsk rally. Gov. Sergei Furgal has been in a Moscow jail since his July 9 arrest on charges of involvement in murders that occurred in 2004 and 2005. He has denied the charges. His supporters see the charges as unsubstantiated.