Muslim religious leaders removed from a Minneapolis flight last week exhibited behavior associated with a security probe by terrorists and were not merely engaged in prayers, according to witnesses, police reports and aviation security officials.

Witnesses said three of the imams were praying loudly in the concourse and repeatedly shouted "Allah" when passengers were called for boarding US Airways Flight 300 to Phoenix.

"I was suspicious by the way they were praying very loud," the gate agent told the Minneapolis Police Department.

Passengers and flight attendants told law-enforcement officials the imams switched from their assigned seats to a pattern associated with the September 11 terrorist attacks and also found in probes of U.S. security since the attacks -- two in the front row first-class, two in the middle of the plane on the exit aisle and two in the rear of the cabin.

"That would alarm me," said a federal air marshal who asked to remain anonymous. "They now control all of the entry and exit routes to the plane."

A pilot from another airline said: "That behavior has been identified as a terrorist probe in the airline industry."

But the imams who were escorted off the flight in handcuffs say they were merely praying before the 6:30 p.m. flight on Nov. 20, and yesterday led a protest by prayer with other religious leaders at the airline's ticket counter at Ronald Reagan Washington National Airport.

Mahdi Bray, executive director of the Muslim American Society Freedom Foundation, called removing the imams an act of Islamophobia and compared it to racism against blacks. "It's a shame that as an African-American and a Muslim I have the double whammy of having to worry about driving while black and flying while Muslim," Mr. Bray said.

The protesters also called on Congress to pass legislation to outlaw passenger profiling. Rep. Sheila Jackson-Lee (right), Texas Democrat, said the September 11 terrorist attacks "cannot be permitted to be used to justify racial profiling, harassment and discrimination of Muslim and Arab Americans."

"Understandably, the imams felt profiled, humiliated, and discriminated against by their treatment," she said.

According to witnesses, police reports and aviation security officials, the imams displayed other suspicious behavior.

Three of the men asked for seat-belt extenders, although two flight attendants told police the men were not oversized. One flight attendant told police she "found this unsettling, as crew knew about the six [passengers] on board and where they were sitting." Rather than attach the extensions, the men placed the straps and buckles on the cabin floor, the flight attendant said.

The imams said they were not discussing politics and only spoke in English, but witnesses told law enforcement that the men spoke in Arabic and English, criticizing the war in Iraq and President Bush, and talking about al Qaeda and Osama bin Laden.

The imams who claimed two first-class seats said their tickets were upgraded. The gate agent told police that when the imams asked to be upgraded, they were told no such seats were available. Nevertheless, the two men were seated in first class when removed.

A flight attendant said one of the men made two trips to the rear of the plane to talk to the imam during boarding, and again when the flight was delayed because of their behavior. Aviation officials, including air marshals and pilots, said these actions alone would not warrant a second look, but the combination is suspicious.

"That's like shouting 'fire' in a crowded theater. You just can't do that anymore," said Robert MacLean, a former air marshal.

"They should have been denied boarding and been investigated," Mr. MacLean said. "It looks like they are trying to create public sympathy or maybe setting someone up for a lawsuit."

The pilot with another airline who talked to The Washington Times on condition of anonymity, said he would have made the same call as the US Airways pilot.

"If any group of passengers is commingling in the terminal and didn't sit in their assigned seats or with each other, I would stop everything and investigate until they could provide me with a reason they did not sit in their assigned seats."

One of the passengers, Omar Shahin, told Newsweek the group did everything it could to avoid suspicion by wearing Western clothes, speaking English and booking seats so they were not together. He said they conducted prayers quietly and separately to avoid attention.

The imams had attended a conference sponsored by the North American Imam Federation in Minneapolis and were returning to Phoenix. Mr. Shahin, who is president of the federation, said on his Web site that none of the passengers made pro-Saddam or anti-American statements.

The pilot said the airlines are not "secretly prejudiced against any nationality, religion or culture," and that the only target of profiling is passenger behavior.

"There are certain behaviors that raise the bar, and not sitting in your assigned seat raises the bar substantially," the pilot said. "Especially since we know that this behavior has been evident in suspicious probes in the past."

"Someone at US Airways made a notably good decision," said a second pilot, who also does not work for US Airways.

A spokeswoman for US Airways declined to discuss the incident. Aviation security officials said thousands of Muslims fly every day and conduct prayers in airports in a quiet and private manner without creating incidents.