The Dutch government has summoned the Russian ambassador to the Netherlands after a Dutch diplomat was beaten in Moscow yesterday.
Dutch media said the diplomat suffered minor injuries.
The incident comes a week after President Vladimir Putin demanded an apology for the alleged beating of a Russian diplomat in the Netherlands.
A Russian police source told Interfax the Dutch diplomat in Moscow had reported that assailants broke into his apartment, beating him and leaving "a heart with the letters LGBT" on the diplomat's wall.
LGBT is an acronym for lesbian, gay, bisexual and transgender.
Interfax's police source said he did not ask for medical treatment.
The Moscow attack resembled Russia's version of the incident in which it said a minister-counsellor at its embassy in The Hague was badly beaten in his home in front of his children by armed assailants.
The Russian embassy said he was beaten with a police baton.
Dutch police have not commented on the charge that he was beaten with a police baton, but did confirm that he was detained illegally in violation of the right to diplomatic immunity.
The Netherlands has apologised for the detention of the Russian diplomat.
Dutch child protection services said after the incident they were investigating a complaint from neighbours of diplomat Dmitry Borodin about his treatment of his children.