An anti-government protest erupted in Russia's far eastern city of Khabarovsk on Saturday.
Thousands gathered in a central square and some shouted, "Shame on Moscow!", "Putin's a thief!" and "Down with the tsar!" referring to President Vladimir Putin.
They were upset after Sergei Furgal, the popular governor of their region who was arrrested on Thursday and flown to Moscow on murder charges.
Russia's main criminal investigation body says he is suspected of involvement in several murders of businessmen in 2004 and 2005 before his political career began.
Furgal appeared in court in Moscow on Friday and was ordered to remain in pre-trial detention for two months.
Unusually, the police made no attempt to break up Saturday's rally or arrest anyone.
"We have elected him, and it's up to us to judge him. We support him and don't understand the reason he was taken to Moscow," one protester said as he marched.
"I want him to be released and to stay. None of these speculations have been proved. We support Furgal and demand his release," another protester said.
Other protests broke out in smaller cities in the region.
Furgal beat President Putin's candidate for governor by a landslide in elections two years ago.
His unexpected victory reflected growing public frustration with Putin's policies and marked a painful setback for the main Kremlin party, United Russia.
The protest was the biggest in the region for decades, which is an eight-hour flight from Moscow.