The main figures who stand against Vladimir Putin and his United Russia party

Alexey Navalny

The charismatic 35-year-old lawyer is seen as the de facto leader of Russia's disparate opposition, the first one able to unite liberals, nationalists, young and old. He coined the term "party of crooks and thieves" to describe Vladimir Putin's United Russia party. His blog, launched as a vehicle to expose his anti-corruption work, is visited by tens of thousands of people daily. He was arrested at Monday's protest and jailed for 15 days.

Ilya Yashin

Yashin, 28, is one of the youngest leaders opposed to Putin's rule and a co-leader of Solidarity, an umbrella liberal opposition movement. He is a constant presence at Russia's "Strategy 31" protests, where liberal activists meet on the 31st of each month to call for the right to protest. They are regularly broken up by police. Yashin was arrested on Monday and sentenced to 15 days in prison for disobeying police orders. He has been targeted several times by Nashi, the pro-Kremlin youth group.

Boris Nemtsov

Nemtsov, 52, has been an outspoken critic of Putin for nearly a decade. The party he helped co-found, Parnas, was denied the right to register in parliamentary elections this year. He is seen as part of the older generation of liberal critics, and is somewhat tainted by his association with the late president Boris Yeltsin, under whom he served as deputy prime minister during some of the country's most chaotic years. He is also well known for his playboy lifestyle.

Yevgeniya Chirikova

Chirikova built her name by leading the fight against a project to build a highway through the Khimki forest in northern Moscow. The eloquent 35-year-old has become the new face of grassroots activism in Russia.

• The first Russian motherboard based on ARM-processor Baikal-M