The FBI is trying to determine whether members of a radical Detroit-area Islamic group were homegrown jihadists or merely a "bunch of thugs with bluster," a congressman said Thursday. One thing is certain: They are not mainstream Muslims, the agency said.

Luqman Ameen Abdullah skimmed 20 percent of the profit off the furs, electronics and other items his followers fenced, and he preached that it was OK for them to steal as long as they prayed, FBI agent Gary Leone wrote in an affidavit filed with a criminal complaint against 11 group members.

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Abdullah, 53, was killed Wednesday in a shootout with agents after the FBI raided a suburban warehouse the group used. Eight members, including Abdullah's son, have been arrested and authorities were seeking the public's help in capturing the other two. The group members are charged with various federal crimes, chiefly conspiracy to sell stolen goods.

The FBI says Abdullah, also known as Christopher Thomas, was an imam of a local faction of Ummah, a group that seeks to establish an Islamic state within the United States. Authorities say Abdullah preached hate for the government and encouraged his followers to commit violence, especially against police and federal agents.

According to the affidavit, Abdullah told a confidential FBI source that if the government messed with him, "it will be straight up war."

Andrew Arena, the head of the FBI's Detroit office, stressed Thursday that Abdullah's mosque, Masjid Al-Haqq, was in no way representative of the Detroit area's large Muslim community.

"This is a very hybrid radical ideology. I don't know that I'd call it a religion," Arena said.

Among Arab-Americans, there's a fear "this is going to be portrayed as another al-Qaida sleeper cell in the United States and this is going to bring unwanted attention. ... That's certainly not the way we feel," Arena said.

The government has not charged Abdullah's followers with terrorism-related charges, and Arena and U.S. Attorney Terrence Berg declined to comment about whether they planned to do so. A criminal complaint is a temporary charge that typically is followed by an indictment.

Berg said Abdullah's group's anti-government beliefs motivated them to commit crimes, but he declined to elaborate.

Rep. Peter Hoekstra of Michigan, the top Republican on the House Intelligence Committee, said he talked to FBI Director Robert Mueller and was told the agency was trying to determine if the men were a "bunch of thugs with bluster" or possible homegrown jihadists.

Ummah is a movement with no apparent central religious authority, so it's difficult to say what the group's factions teach in their mosques.

In Warren, a Detroit suburb, local imams met privately with Arena and Berg to discuss the arrests. They were joined by Imam Mutawaf Shaheed of Cleveland, who identified himself as a representative of Ummah. He said the mission is to "spread charity, good faith and understanding about Islam" — not overthrow the government.

The FBI said at least five of the 11 people charged by the government have felony convictions, including Abdullah, who was convicted of assault and carrying a concealed weapon in Detroit in 1981.

Gary Porter, 59, was arrested Wednesday at A.L. Holmes Elementary School in Detroit, where he teaches gym. He's charged with conspiracy and being an ex-convict in possession of guns or ammunition.

Two suspects were still at large: Yassir Ali Khan, 30, of Warren and Ontario, and Mohammad Philistine, 33, of Ontario.

Abdullah's mosque is at a two-family flat next to a boarded-up house in Detroit. His group was evicted from another location this year because of nonpayment of property taxes.

Jamil Ibm Rafael, 60, identified himself as the mosque's lone security officer. He said the FBI's portrayal of Abdullah was "fabricated," but he acknowledged that members often speak out against the government.

"They are making up stuff. It's a war against Islam," Rafael said of authorities.

Arena said a search of a Detroit duplex where Abdullah lived turned up weapons, including an M-16 assault rifle.

"The person I knew and the person who lives here is not the person ... that is on TV with all the allegations," said Joseph Taylor, 44, who lived above Abdullah for about 10 years.

The FBI penetrated his group with the help of confidential informants who recorded conversations with Abdullah. A year ago, the FBI hatched an undercover operation in which Abdullah and others believed they were selling stolen goods worth more than $5,000.

The FBI said Abdullah received at least 20 percent, telling allies that it's the way "dirty money is purified."