PRAGUE, Czech Republic, May 2 (UPI) -- Czech authorities filed charges against four protesters who clashed with riot police in the eastern city of Brno during a May Day rally, media said.

Brno police arrested the four supporters of the far-right National Resistance movement on charges of attacking public officials, Prague Radio reported Wednesday.

If found guilty and convicted the four could face up to five years in jail.

Two journalists and seven police officers were injured in the Brno clashes when rightist supporters hurled stones and bottles at riot police.