Police detained about 55 protesters on Sunday outside the gates to Red Square, which was unexpectedly closed to all visitors and tourists to prevent an anti-Kremlin demonstration. Opposition activists had called on supporters to walk around the square wearing the white ribbons that have become a symbol of the protest movement against Vladimir Putin and the stifling of democratic politics during his 12 years in power.

When police took the unusual step of closing the vast cobblestone square near the Kremlin, about 300 protesters gathered instead just outside the gates. The meeting place, communicated through social networking sites, was the "zero kilometre", the spot from where all distances from Moscow are measured.

Holding hands to form a circle, the protesters chanted "This is our city", "Russia will be free" and "Russia without Putin". Some of the protesters then demanded to be allowed onto Red Square and police rounded them up, leading or carrying them onto waiting buses.