The European Union has strongly condemned Russia for banning Polish and Latvian officials from entering the country to attend slain Kremlin critic Boris Nemtsov's funeral.

European Parliament President Martin Schulz has called it a "high affront" which will further set back relations with Moscow.

He said Tuesday he will intervene with Russian authorities "in the strongest terms and demand an official explanation." Latvia holds the rotating EU presidency. The European Commission, Latvia and Poland also joined the protest.

Schulz says that the Russian moves "are being applied without the slightest element of reasoning or any forewarning."

In the wake of the fighting in eastern Ukraine and Moscow's annexation last year of the Crimean Peninsula, the EU has imposed visa bans on 151 individuals, including several Russians.