Large groups of young people clashed with Estonian police for a second night Friday over the removal of a Red Army Soviet statue.
One man has already died in riots over the government's move.
On the streets of Estonia's capital city Tallinn, gangs of Estonian and Russian teenagers shadowed each other shouting 'Russia, Russia' or 'Estonia, Estonia'.
More than 200 riot police sprayed fire extinguishers and a water cannon at the crowd.
Young people smashed the windows of dozens of shops.
Estonians believe the two-metre high bronze statue at the centre of the violence was a reminder of 50 years of Soviet occupation.
The Russian-speaking minority make up one quarter of Estonia's population.
Moscow's upper house of parliament voted to ask President Vladimir Putin to sever relations with the Baltic state.
Russia's Foreign Minister Sergei Lavrov did not specify what measures his country was considering against its former state.
Speaking at a same NATO meeting in Oslo where Russian president Vladimir Putin declared a moratorium on the CFE arms treaty one day ago, Minister Lavrov said this current issue is of interest to Estonia, Russia and Europe as it touches on European values.
