Sunday's event saw a smaller turnout than many previous opposition protests last summer, which at their peak drew around 60,000 people.

Video shows the moment two helmeted riot policemen drag the woman, Daria Sosnovskaya, to a waiting police bus.

A month of demonstrations over elections for the Moscow city legislature have turned into the biggest sustained protest movement in Russia since 2011-2013, when protesters took to the streets against perceived electoral fraud.