Russian investigators on Tuesday launched a probe into "mass unrest", a crime punishable by up to 15 years in
prison, after thousands took to the streets at the weekend to demand fair elections.
Nearly 1,400 people were arrested on Saturday at an unauthorised protest in central
Moscow that was broken up by baton-wielding riot
police, as anger grows against authorities' refusal to allow prominent opposition candidates to stand for the city parliament.
The crackdown was the largest of its kind since 2012, when tens of thousands of people came out to protest Vladimir Putin's return to the presidency after four years as prime minister.