BRUSSELS, May 3 (Xinhua) -- NATO issued a statement on Thursday, expressing its deep concern over the safety of its member state Estonia's embassy in Moscow.

    "NATO is deeply concerned by threats to the physical safety of Estonian diplomatic staff, including the ambassador, in Moscow, as well as intimidation at the Estonian Embassy," the statement said.

    "These actions are unacceptable, and must be stopped immediately; tensions over the Soviet war memorial and graves in Estonia must be resolved diplomatically between the two countries," it added.

    NATO also urged the Russian authorities to implement their obligations under the Vienna Convention on diplomatic relations.

    Estonian Foreign Minister Urmas Paet has lodged a strong protest with Russia after an alleged attack on the Baltic nation's ambassador by Russian protestors.

    The protestors have blockaded the embassy for nearly a week as tension builds up over the removal of a statue of a Red Army soldier -- a symbol of Soviet soldiers killed during World War II -- from Tynismyagi square in Tallin.