The plane’s on the runway in Boston now; passengers are being offloaded. Details are sketchy, but Fox said there were three “suspicious” people onboard who confronted the crew and who may or may not have had an “item” or “items” with them.

No red font for the headline since this is probably nothing. But stand by.

Update: CNN quotes an unnamed fed as saying there was no terrorism involved. Fox quotes an FBI agent as saying the incident might have been caused by a claustrophobic female passenger, with other passengers “getting involved.”

Sounds like there’s nothing to see here. Just bad luck that it happened on a flight from London.

Update: Fighter jets escorted the plane in, but that, alas, appears to be SOP these days.

Update: Here’s the report from WBZ in Boston:

A United Airlines flight from London to Washington D-C was diverted to Logan Airport this morning following a confrontation involving three passengers.

A woman on board Flight 923 apparently became “unruly,” prompting the pilot to request an emergency landing at Logan shortly after 10 a-m.

Update: All right, this gets the red font: Fox just said the woman had a note referencing Al Qaeda, along with “vaseline,” matches, and a screwdriver.

Update: For what it’s worth, today’s the day the terror plot was allegedly supposed to have taken place.

Update: The pilot on the flight had declared a “security emergency.”

Update: CNN says there’s an unconfirmed report that the woman was tied up.

Update: CNN asks a good question. Regardless of whether this was terror or just a lone nut, how’d she get vaseline and matches through the screeners at a British airport? Here’s a better question: why was it left to the crew to confront the passenger? There wasn’t a federal air marshal on a flight from London to Washington? On the very day the attacks were supposed to have occurred?

Update: CNN confirms that she had two notes — one in English, the other in Arabic.

Update: Bomb-sniffing dogs are checking the bags.

Update: Fox says an undersecretary at TSA is denying that the woman had any notes or items on her, which puts us back at claustrophobia. Very strange to have two competing storylines like this.

Update: Two storylines:

An FBI spokeswoman in Boston said the incident involved one “disruptive,” 60-year-old female passenger who was reportedly claustrophobic…

Logan Airport spokesman Phil Orlandella said the woman had Vaseline, a screw driver, matches and a note referencing al-Qaida.

Which storyline you believe depends upon your ideology, of course. Lefties will accuse the feds of making up the stuff about the note and vaseline in order to spread panic. Righties will accuse the feds of making up the stuff about claustrophobia in order not to spread panic.

Dean Barnett e-mails:

So she became claustrophobic, got unruly, and wrote a note in Arabic referencing Al Qaeda?

I usually write the Arabic note first when I get claustrophobic.

Update: More from NBC:

A female passenger aboard United Flight 923 said she was claustrophobic and became very upset and got into some kind of confrontation with the flight crew, according to George Naccara, federal security director for the Transportation Security Administration for Massachusetts’ airport…

NBC News has been told there was never a threat of terrorism. The pilot decided to land at the nearest airport after the altercation. The woman was taken off the plane, which is planned to continue to Dulles International Airport.

How did the stuff about the vaseline and note get started?

Update: Heads up, ladies: no more gel bras on airplanes.

Update: More from the Blotter:

Police at Logan Airport tell ABC News that a full search is underway of the passenger jet. The female passenger who originally aroused suspicions has already been searched, and so far authorities have recovered a bottle of petroleum jelly, a bottle of water and literature in what appears to be Arabic but could turn out to be another language. A translator has been summoned to determine language and contents.

A senior homeland security official in Massachusetts tells ABC News that so far neither a screwdriver nor a note referencing al Qaeda has been found contrary to previous media reports.

Update: AosHQ regular (and guest-blogger) SarahW e-mails re: air marshals:

They must be trained to watch out for diversion techniques, aren’t they? I don’t know if there were air marshals on that flight; however, it would seem to be one day they would indeed wait to announce themselves until it was clear the crew could not control matters, as opposed to popping out of their tourist disguise, and possibly getting picked off by snakes on the plane.

Update: A spokesman for United says the woman was engaged in “suspicious activity,” but that could mean a lot of things.