"It was a murder," Leonid Volkov, a close collaborator of the opposition, said on Telegram on Saturday. The United States ambassador to Russia visited an improvised memorial in Moscow in tribute to the deceased opponent.
Navalny was serving a 19-year sentence for "extremism," and was perceived by many as the best hope for change in Russia. Human rights groups reported that nearly 800 people were detained at rallies in memory of Navalny, who died at age 47 in the Arctic prison where he was being held.