KALININGRAD, December 8 (RAPSI) - Polish officials have begun prosecuting their citizens who are fighting on behalf of the East Ukrainian militia, the Polish Culture and Business Center in Kaliningrad reported on Monday citing Polish media.

The first criminal case was opened by the Prosecutor’s Office in Bielsko-Biała against a 29-year-old Great Poland Camp activist who is fighting in southeastern Ukraine alongside the self-defense forces. It was reported that he was discovered by the Polish National Security Bureau.

The security services first became alarmed by the activist’s message in social media where he wrote that he will not “sit at his computer” while the West is “attacking” his neighboring country.

The bureau intends to notify the prosecutor’s offices in Katowice and Szczecin concerning two more Polish citizens currently fighting in Ukraine on behalf of the militia. Under Polish law, serving in a foreign army is prohibited and is punishable by up to five years in prison.

Kiev launched a military operation in mid-April to suppress the anti-Maidan movement in eastern Ukraine, which did not recognize the legitimacy of the February coup in Kiev.