CHICAGO (WLS) -- A man who federal investigators say pledged allegiance to the domestic terror group "Army of God" is facing charges connected with a threat to bomb and burn down Chicago-area abortion clinics.Luke Wiersma from Dyer, Ind., appeared in federal court late Wednesday after threatening to blow up an abortion clinic to stop the "unmitigated murders of fetuses." According to court records he also outed himself to federal authorities by sending anonymous tips into the FBI warning of his intention."Luke Wiersma is a danger to society. He plans on committing crimes against abortion clinics. He has threatened to 'do whatever is necessary to stop the unmitigated murders of fetuses at baby killing mills.' I don't know what he meant but I think he is possibly planning a violent attack," anonymous messages to the FBI read.Wiersma, 33, currently faces up to six years in prison for his threats to burn down abortion clinics in Hammond and Chicago. He agreed to meet Tuesday with FBI agents where he confessed to both sending threats and messages to the FBI tipping them off to his plans, records state.Wiersma said he was a member of the Army of God, identified by investigators as a Christian domestic terrorist organization. The group has taken responsibility in the past for bombing an Alabama abortion clinic."You will all f-ing pay for what you do. If not by my hand it will be by somebody else's," is one message that federal prosecutors say Wiersma sent to a Chicago clinic's website read. "I want you to burn, I want you all to Die" he wrote, according to court records. "I will kill to stop these atrocities. I will blow you up if I have to, burn the clinic down. I will do whatever is necessary I swear to God I will. After that you are in God's hands and He will do His thing."Wiersma is being held without bond at the MCC-Chicago. A bond hearing is scheduled for Friday.