Police in Russia have arrested around 1,500 people at protests in Moscow and St Petersburg called by opposition leader Alexei Navalny.
A Russian NGO tracking the arrests said a total of 823 people were detained in Moscow with 600 arrested in St Petersburg.
Mr Navalny himself was also arrested and swiftly jailed for 30 days for organising the protests.
He was detained near the entrance to his home earlier today as he was heading to the protest venue.
In Moscow's Pushkin Square around 1,000 protesters started to move towards the Kremlin, but their path was blocked by police barriers put in place as part of a festival of historical costumes on Tverskaya Street, Moscow's central thoroughfare.
A witness has said police have put on gas masks and tear gas was used on protesters.
An AFP correspondent said demonstrators flocked to protest in the centre of St Petersburg after authorities allowed them to gather only in a far-off spot in the north of the city.
