The feds are going hard on the anti-ICE demonstration Don Lemon covered at a Minnesota church … because dozens more protestors are going to be arrested.

According to a superseding federal indictment, obtained by TMZ, the feds are charging 30 new people. Don and 8 others were already arrested and charged in relation to the January 18 protest.

The feds say a group of approximately 40 “agitators” went into Cities Church in St. Paul in a “coordinated takeover-style attack and engaged in acts of oppression, intimidation, threats, interference, and physical obstruction.”

Don was there, filming it all for his live stream … and he got charged with federal crimes, even though he said he was there solely as a journalist. Don has already pleaded not guilty.

Our sources tell us the feds are going to be making arrests today.

In the indictment, the feds claim one protestor disrupted the service by chanting, “This ain’t God’s house. This is the house of the devil.” The feds say the protestor also screamed “Nazi” in congregants’ faces and asked a child, “Do you know your parents are Nazis? They are going to burn in hell.”