In pictures: Tens of thousands gather for pro-Navalny protests

Tens of thousands of people rallied across Russia on Saturday in some of the largest demonstrations held against President Vladimir Putin in years.

Crowds defied police to show support for opposition leader Alexei Navalny - who was arrested last weekend after returning to the country following a near-fatal nerve agent attack last year.

Monitors say more than 3,000 were arrested for taking part in rallies in dozens of cities across the country.

Reuters estimated that some 40,000 gathered in Moscow alone, but authorities played down the figure and said only a tenth of that number showed up.