KYIV, Feb. 27 – Three Poles from apparently a pro-Russian group were detained by Polish security agency on Tuesday in Poland after allegedly perpetrating an arson attack on a Hungarian cultural center in Ukraine, PAP reported.

The attack in Uzhgorod triggered an international scandal straining relations between Ukraine and Hungary, which had previously threatened to block Ukraine’s relations with NATO.

Viktor Kononenko, the deputy head of the Security Service of Ukraine, said, the arsonists acted on behalf of the Russian special services, PAP reported.

The developments underscore a hidden and devastating role that Russian special services are playing to try to undermine Ukraine’s pro-Western foreign policies.

Uzhgorod is located in the Zakarpattia region in southwestern Ukraine, which has a Hungarian minority of 150,000.

Hungary's Foreign Ministry has summoned the Ukrainian ambassador to warn against rising "extremism" after an ethnic Hungarian cultural center in western Ukraine was attacked for the second time in a month.

The headquarters of an ethnic Hungarian cultural association was set on fire overnight in Uzhhorod, capital of the Transcarpathia region, according to Hungarian news agency MTI.

A Molotov cocktail was thrown into the building and caused a fire that destroyed most of the ground floor, MTI said. There were no reports of injuries.

The building also suffered minor damage in an attack on February 4, when an unidentified person threw a Molotov cocktail through the window.

"Extremist political views" are gaining ground in Ukraine and intimidating ethnic Hungarians, Hungarian Foreign Minister Peter Szijjarto told public television channel M1 on February 27.

"All of this is unacceptable," Szijjarto said.

Ukrainian Foreign Minister Pavlo Klimkin wrote on Twitter early on Tuesday, "I firmly denounce yet another provocation in Uzhhorod against the Hungarian minority office."

The attacks come as Budapest and Kyiv remain at odds over an education law passed by Ukraine in September 2017 that Hungary and Romania say restricts the right of Ukraine's Hungarian and Romanian ethnic minorities to be educated in their native language.

Kyiv maintains the law is meant to ensure that all Ukrainian citizens can speak the state's official language, and it denies that the law is discriminatory.

Ukraine has also criticized Budapest's move to block cooperation between Kyiv and both the European Union and the NATO until the dispute is resolved. (pap/ez)