A Polish diplomat was beaten near the embassy building in the Russian capital on Wednesday, marking the second such attack in recent days.
The Interfax news agency named the diplomat as Second Secretary Marek Reszuta and quoted police officials as saying that four people attacked him. The diplomat has been hospitalized with light injuries and a suspected concussion, the AP reports.
On Monday, the Foreign Ministry assured security around the mission would be stepped up after a Polish Embassy employee was severely beaten over the weekend.
Some 10 days ago, still-unidentified attackers attacked three sons of Russian diplomats in Warsaw and stole their mobile phones. Russia demanded an apology, claiming anti-Russian attitudes had inspired the attack.
The Polish Foreign Ministry has expressed "deep regret" over the assault, but said it owed no apology for what it said was a crime with no political intent.