MOSCOW — The year 2013 was officially supposed to be one of cultural exchange to highlight the friendship between Russia and the Netherlands. But lately, the most common exchanges between officials have been threats and legal actions amid an intensifying quarrel over the arrest and prosecution of Dutch citizens detained by the Russian Coast Guard aboard a Greenpeace ship flagged in the Netherlands.

On Wednesday, Dutch officials were demanding an investigation after the beating of a senior diplomat in his apartment here. Two men forced their way into the apartment of Onno Elderenbosch, the Netherlands’ deputy ambassador to Russia, and attacked him late Tuesday night, said Friso Wijnen, a spokesman for the Dutch Foreign Ministry. Mr. Elderenbosch sustained minor injuries, he said.

Russian news media outlets reported that Mr. Elderenbosch’s attackers were disguised as electricians, and taped his hands together before attacking him. A news service published photographs of damaged furniture in the apartment and reported that the two attackers had scrawled a heart and the letters LGBT, for lesbian, gay, bisexual and transgender, in pink lipstick on a mirror before fleeing the scene.

The Russian Foreign Ministry on Wednesday tried to head off any political fallout from the attack on Mr. Elderenbosch, deploring the episode and promising to take steps to detain the two attackers, who remained unidentified as of Wednesday evening. Russian law enforcement officials said a criminal investigation into the attacks had been opened.