Estonian police clashed with large groups of youths for a second night after the removal of the statue of a Red Army Soviet soldier and the death of one man in previous riots. The authorities took the monument away early yesterday, saying it was a public order problem as it attracted Estonian and Russian nationalists.
Russia reacted furiously to the monument being moved and its upper house of parliament voted to ask President Vladimir Putin to sever relations with the Baltic state.
Foreign Minister Sergei Lavrov said Moscow would "take serious steps".
In the capital city, Tallinn, gangs of Estonian and Russian youths and teenagers shadowed each other around the streets yesterday evening, shouting "Russia, Russia" or "Estonia, Estonia". In one central square, near the site where the statue had stood, around 200 to 300 police dressed in riot gear sprayed fire extinguishers at the crowd, set off blank explosives and used a water cannon.
A police spokesman said around 100 people had been detained and 10 people injured. Police attempted to keep people from gathering in large numbers and away from the monument site. Youths smashed the windows of dozens of shops.
The bronze statue of a World War Two Red Army soldier was moved after the worst violence in years in Estonia, including vandalism and looting by mainly Russian-speaking protesters on Thursday night.
"The aim of the ... decision was to avoid further possible actions against public order," the government said.
Removing the statue angered some Russian-speakers, who number about 300,000 in a country of 1.3 million.
Estonians tend to view it as a reminder of 50 years of Soviet occupation. Estonia said one man died in the disturbances, which began after more than 1,000 people gathered to protest against the plan to remove the statue on Thursday. He was stabbed.
Police arrested 300 people, while 44 protesters and 13 police were hurt. Looters set fires and damaged cars.
Russia, which has had troubled ties with Estonia since the 1991 collapse of the Soviet Union, had protested against moving the monument as an insult to those who fought against fascism. Russia's Foreign Ministry did not specify what measures it was considering against Estonia. Mr Lavrov, at a NATO meeting in Oslo, said the issue was of interest to Estonia, Russia and to Europe as it touched on European values.