"The Prosecutor's Office sent an indictment to the court following an investigation ... into the suspects over the preparation of a crime of creating a situation threatening the life and health of multiple people or large property as a result of an explosion," Stanislaw Zaryn said at a briefing.

According to the ABW, suspects plotted an attack "at a particular object of religious worship of the Muslim community and planned to disperse poisonous substances," feeling strong opposition to the "Islamization of Poland."

Security officers found and confiscated from them explosive substances, four guns, including a hand-made automatic pistol, and munitions, as well as tools and materials for producing hazardous substances, according to Zaryn.

One of the detained suspects was described as "inciting violence, crime and hatred based on national, ethnic, race and religious background," the spokesman said.

The indicted persons face prison sentences up to 10 years.