In a telephone conversation with Estonian President Toomas Hendrik, EU High Representative for the Common Foreign and Security Policy Javier Solana urged Estonia to avoid violence and defuse tensions, Solana's press secretary said.
She said the EU official endorsed Estonia's "constructive action" to normalize the situation, adding the war memorial issue was not an EU problem, but a bilateral problem of Russian-Estonian relations and should be solved through dialogue.
Russia demanded earlier Saturday that Estonian authorities provide information on a Russian national killed in clashes with police.
"We express condolences to the family and friends of the dead man and demand Estonian authorities provide full information on what happened, promptly conduct an investigation and bring those guilty to justice," the ministry said.
Estonia's Interior Ministry said a criminal case has been opened and the investigation is under way.
Police said the Russian man, named Dmitry and aged 28 or 29, had been stabbed in the chest and later died in hospital.
They said there is no evidence to suggest that he died as a result of police action.
Latest police reports said about 800 people had been arrested between Thursday night and Saturday morning in Tallinn, where police used tear gas and water cannons to disperse protestors, who smashed windows of buildings near the Soviet-era Bronze Soldier statue in the city center, damaged bus stops and parked cars and set billboards on fire. Sixty people, including police officers, have been injured.
Estonian police have not disclosed the whereabouts of those arrested.
"After consultations with the prosecutor's office, we made a decision that police should not disclose where people detained during mass riots on Thursday and Friday are being held," Taavi Kullerkupp from the press service of a police precinct in Tallinn said Saturday.
A public organization, Night Watch, said Estonian police brutally beat detainees.
"Police knocked some of them to the ground and beat them with sticks, aiming for the heart and stomach. Many of those who tried to stand were beaten on the legs. Even a girl was attacked," said Yury Zhuravlev, a member of Night Watch.
He said he was among a group of detainees taken to a warehouse at Tallinn Sea Port.
"Initially there were about 300 people but then [their number rose to] around 450, including those who had taken part in the protest action and people who just happened to be in the street at the time, and who did not even know why they had been detained," he said.
Zhuravlev said there were several young women and foreign correspondents among those arrested.
He said some of them were released during the night, while the rest were freed around 4 a.m. [midnight GMT].
The protests erupted after Estonian authorities cordoned off the area around the Soviet World War II memorial Thursday in the run-up to Victory Day May 9. They decided to dismantle and relocate the Bronze Soldier early Friday, when protests turned into violent riots.
Estonia has said the Bronze Statue and other Soviet monuments - rallying points for ethnic Russians and places of their clashes with Estonian nationalists - "divide society," and the central square is not a proper burial place.
The Foreign Ministry said Russia, which has repeatedly voiced concerns over discrimination against ethnic Russians in Estonia and the other ex-Soviet states in the Baltics, hoped "international, above all European, organizations and European officialdom will take a sharply critical position [on the events in Tallinn] without double standards."
European bodies have made no comment on the dismantling of the monument in Estonia so far.