Briefly, the following events occurred. Thirteen Middle Eastern men were traveling together as a musical group, 12 carrying Syrian passports and one, a lawful permanent resident of the United States of Lebanese descent, purchased one-way tickets from Detroit to Los Angeles. Six of the men arrived at the gate together after boarding began, then split up and acted as if they were not acquainted. According to air marshals, the men also appeared sweaty and nervous. An air marshal assigned to Flight 327 observed their behavior and characterized it as "unusual," but made no further reports at the time.

During the flight, the men again acted suspiciously. Several of the men changed seats, congregated in the aisles, and arose when the fasten seat belt sign was turned on; one passenger moved quickly up the aisle toward the cockpit and, at the last moment, entered the first class lavatory. The passenger remained in the lavatory for about 20 minutes. Several of the men spent excessive time in the lavatories. Another man carried a large McDonald's restaurant bag into a lavatory and made a thumbs-up signal to another man upon returning to his seat.

Undercover federal air marshals on board a June 29 Northwest airlines flight from Detroit to LAX identified themselves after a passenger, "overreacted," to a group of middle-eastern men on board, federal officials and sources have told KFI NEWS.

The passenger, later identified as Annie Jacobsen, was in danger of panicking other passengers and creating a larger problem on the plane, according to a source close to the secretive federal protective service.

"The lady was overreacting," said the source. "A flight attendant was told to tell the passenger to calm down; that there were air marshals on the plane."

The middle eastern men were identified by federal agents as a group of touring musicians travelling to a concert date at a casino, said Air Marshals spokesman Dave Adams.

Jacobsen wrote she became alarmed when the men made frequent trips to the lavatory, repeatedly opened and closed the overhead luggage compartments, and appeared to be signaling each other.

"Initially it was brought to [the air marshals] attention by a passenger," Adams said, adding the agents had been watching the men and chose to stay undercover.

Jacobsen and her husband had a number of conversations with the flight attendants and gestured towards the men several times, the source said.

"In concert with the flight crew, the decision was made to keep [the men] under surveillance since no terrorist or criminal acts were being perpetrated aboard the aircraft; they didn’t interfere with the flight crew," Adams said.

The air marshals did, however, check the bathrooms after the middle-eastern men had spent time inside, Adams said.

FBI agents met the plane when it landed in Los Angeles and the men were questioned, and Los Angeles field office spokeswoman Cathy Viray said it's significant the alarm on the flight came from a passenger.

"We have to take all calls seriously, but the passenger was worried, not the flight crew or the federal air marshals," she said. "The complaint did not stem from the flight crew."

Federal agents later verified the musicians' story.

'We followed up with the casino," Adams said. A supervisor verified they were playing a concert. A second federal law enforcement source said the concert itself was monitored by an agent.

"We also went to the hotel, determined they had checked into the hotel," Adams said. Each of the men were checked through a series of databases and watch-lists with negative results, he said.

The source said the air marshals on the flight were partially concerned Jacobsen's actions could have been an effort by terrorists or attackers to create a disturbance on the plane to force the agents to identify themselves.

Air marshals' only tactical advantage on a flight is their anonymity, the source said, and Jacobsen could have put the entire flight in danger.

"They have to be very cognizant of their surroundings," spokesman Adams confirmed, "to make sure it isn't a ruse to try and pull them out of their cover."

Overall, a key element when considering the response to this incident should be noted, which is that the 13 Syrian musicians were not terrorists and that the law enforcement assessments made by the FAMS and FBI on June 29, 2004 were appropriate.

The decision not to contact the HSOC was decided only after the FAMS and FBI leadership jointly determined that the subjects could be cleared. The reported suspicious activity was determined to be unfounded, and not a terrorist threat ...