Russian authorities sentenced popular journalist and activist Ilya Azar to 15 days in prison for repeat violations of a protest law, he said, sparking outrage among his supporters.

Police detained the 35-year-old municipal lawmaker and journalist for the independent Novaya Gazeta newspaper on Tuesday. He was arrested during a demonstration in support of activist Vladimir Vorontsov, who has worked to expose violations within Russia’s law enforcement agencies.

Vorontsov, a former policeman, was arrested in early May on extortion charges. He was later accused of also illegally distributing pornography.

Vorontsov has denied the charges, saying police are seeking to punish him for his activism. Police said that Azar was being detained for violating a ban on rallies during Moscow’s city-wide quarantine to slow the spread of coronavirus.