Russian MPs have paid their respects at the controversial monument of a Soviet soldier - moved to a new location after riots in the Estonian capital Tallinn.
The Russian MPs expressed outrage at Estonia's action
The statue was re-erected on Monday at a military cemetery in Tallinn, away from the city centre.
But delegates from Russia's Duma said they were not allowed to visit the old site, where Estonia is unearthing coffins of Soviet war dead.
Estonia has protested over what it calls a blockade of its Moscow embassy.
The Estonian ambassador to Russia, Marina Kaljurand, told the BBC's Europe Today programme that up to 500 young people had been "shouting, committing vandalism, writing on the walls of the embassy, throwing stones".
She said their actions meant the embassy "is not secure". The embassies of fellow EU states had voiced support for the Estonian diplomats, she said.
In a separate interview she complained that Moscow police "shrug their shoulders and say that the situation is not under their control".
Estonia's decision to remove the statue of a Red Army soldier sparked riots last week. One Russian died and 153 were injured in the unrest.
1918: Estonia gained independence from Russia
1940: Forcibly incorporated into Soviet Union
1941-1944: Occupied by Nazi Germany
1944: Soviets return as Nazis retreat
1991: Gains independence as Soviet Union collapses
1994: Last Russian forces leave Estonia
Now: Ethnic Russians make up quarter of Estonia's 1.3m people
Estonians say the soldier symbolised Soviet occupation. Russians describe it as a tribute to those who fought the Nazis.
A member of the Duma delegation, Leonid Slutsky, said the Estonian foreign ministry had told the Russian MPs that "members of the public must not attend the exhumation of Soviet soldiers' remains".
"This really blasphemous, inexplicable behaviour by the Estonian authorities won't help the efforts to find mutual understanding," Interfax news agency quoted him as saying.
Tensions have escalated ahead of the World War II Victory Day anniversary on 9 May.
The anniversary is traditionally a day of patriotism and pride for many Russians.
Moscow Mayor Yuri Luzhkov called for "a boycott of all things connected with Estonia," at a May Day rally on Tuesday.
He said Estonia had dismantled the Soviet memorial "in the most barbaric way".
More than a quarter of Estonia's 1.3m people are ethnically Russian, and speak Russian.
However, half of them do not have Estonian citizenship.
During the years of Soviet occupation after the war tens of thousands of Estonians were killed. They say their country was effectively colonised, with many Russians being brought in as workers and military personnel.