Estonian police have used tear gas to disperse crowds protesting against the proposed move of a Red Army war memorial in Tallinn to a cemetery.
Police encircled the memorial while a 2m-high fence went up
The monument and the graves of 14 Soviet soldiers buried nearby were cordoned off early on Thursday morning.
The Russian government says moving the memorial would be an insult to the soldiers who died during World War II.
But Estonia says it poses a risk as it has been the scene of clashes between Estonians and Russian nationalists.
Many Estonians see the bronze statue of a Soviet soldier, erected in 1947 in the centre of Tallinn, as a reminder of nearly 50 years of Soviet occupation.
Estonian riot police formed a ring around the monument at 0430 (0130 GMT) on Thursday, in order to keep protesters away and to allow the construction of a 2m-high wire fence around it.
Regular police continued to patrol the fence's perimeter throughout the day to keep a few dozen protesters, many shouting "Shame on Estonia", from scaling it.
By evening, the crowd of protesters swelled to around 1,000 people and a group tried to break through the police cordon.
Riot police responded by firing tear gas and using water cannon to disperse the crowd.
A spokesman for the Russian foreign ministry said the work showed disregard for the feelings of relatives of the buried soldiers.
He questioned the decision to move it before 9 May, the Soviet Union's Victory Day.
"We are outraged by the fact that the practical steps concerning the monument began shortly before Victory Day, a day that is sacred to everyone," Mikhail Kamynin said.
"We will take into account what is and will be happening today and in the next few days in the Estonian capital while building our relations with this country."
But Estonian Prime Minister Andrus Ansip said the memorial was a matter for Estonia alone.
"We don't consider it necessary to hold deep discussions with the Russian authorities over the internal affairs of Estonia," he said.
"I stress that there has never been any talk in Estonia of demolishing the monument."
"This is a tombstone that will go with any remains we might find, which will be given a decent and dignified reburial."