A Moscow court on Monday sentenced Russian opposition leader Alexei Navalny to 10 days in prison for taking part in a protest in support of a journalist last month, a move which prosecutors deemed to be in violation of Russia’s strict protest laws.

Navalny was one of 400 people detained when police sought to break up the peaceful protest that called for the end of the alleged impunity of law enforcement agencies.

He has faced a string of criminal charges since becoming the leading opposition figure in Russia, campaigning against President Valdimir Putin at past demonstrations.