Catholic Church authorities in eastern Poland have denounced nationalist views and apologized for the actions of radical nationalist organization in a regional cathedral.

Father Andrzej Debski, a spokesman for the church in Bialystok, said Wednesday the apology came after believers complained that a Mass was held in Bialystok Cathedral for the National-Radical Camp, or ONR, celebrating its 82 years on April 16.

The ONR members with flags lined the church's aisle. Debski told The Associated Press that some people complained the priest's speech "was not in line with the spirit of the Gospels."

ONR members then marched in Bialystok, chanting "Down with the European Union!" and "Great Catholic Poland!"

The priest has been banned from making any public statements, and prosecutors are also investigating the situation.