I’m reluctant to raise the alarm before the NYPD’s finished its investigation, but this makes me nervous:

A suspicious vehicle in the heart of Times Square led the police to clear thousands of tourists and theatergoers from the area on a warm and busy Saturday evening…

Police officials said a witness reported a running Nissan Pathfinder with Connecticut plates, with smoke coming out of the back. A bomb squad robot popped the back latch of the Pathfinder, and officers found what they initially believed was a bomb. The vehicle was found to contain explosives, gasoline, propane and burned wires, a Fire Department officer told Reuters.

The officer, who did not give his name because he was not authorized to speak to the news media, said that a man was seen fleeing the S.U.V. and that the police evacuated the area in case there were other threats nearby.

The officer said that the police were treating the vehicle as a “failed device.” The police were searching for a suspect.

What makes me nervous is the use of propane. Remember that London bombing plot three years ago, in which jihadis tried — and failed — to set off a bunch of car bombs around the city? Quote:

The car bombs were similar to highly destructive explosives used in Iraq and could have killed hundreds of people, U.S. and British officials told NBC News. British officials warned that the country was facing a “serious and sustained” terrorist threat…

Authorities believe [the first car] was intended to be set off by remote control by a cell phone found inside. The cell phone had received at least two calls, which should have detonated several gallons of gasoline, but when the calls came in, the bomb failed to go off, the official said.

Had it done so, that blast then would have ignited six to eight tanks of propane in a mist to make a fuel-air explosion, creating a fireball the size of a small house and propelling 18 to 20 boxes of roofing nails around a large area at bullet speed, counterterrorism officials said.

Fuel-air bombs are hugely destructive, as this harrowing Danger Room article published after the London plot broke made all too clear. A fuel-air bomb properly detonated in Times Square on a Saturday night likely would have killed hundreds of people. If that’s what this was — and the feds evidently aren’t sure yet, despite reports of “fireworks” going on in the back seat and someone running away from the vehicle — then there’s a seriously dangerous individual running around NYC right now. Stay tuned. While we wait, check out this PowerPoint presentation generated by the NYPD after the London plot was foiled. The last slide is the one you’re interested in.

Update (5/2): I woke up fully expecting to find that it was a false alarm. Nope. According to CBS NY, this thing was “moments from blowing up.” More from the NYT:

Inside, they discovered three canisters of propane like those used for barbecue grills, two five-gallon cans of gasoline, consumer-grade fireworks — the apparent source of the “pops” — and two clocks with batteries, the mayor said. He said the device “looked amateurish.”

Mr. Browne said: “It appeared it was in the process of detonating, but it malfunctioned.”

Bomb squad officers also discovered a two-by-two-by-four-foot metal box — described as a “gun locker” — in the S.U.V. that was taken to the Police Department’s firing range at Rodman’s Neck in the Bronx to be destroyed, Mr. Kelly said. It was not immediately known what, if anything, was inside it.

Buildings in the vicinity were quickly evacuated, which tells you how seriously they were taking this and how much explosive power they feared the bomb might have. Said Bloomberg, putting it mildly, “We are very lucky.” As for possible culprits, trying to set off a bomb with fireworks doesn’t sound like the work of master jihadis, but then the 2007 London plot was a jihad operation too and that didn’t come off either. The basic ingredients in both plots are the same — propane and gasoline, a.k.a. a fuel-air device. Read this Time magazine piece from five years ago about Al Qaeda capo Dhiren Barot’s “Gas Limo Plot,” which involved packing limousines with tanks of compressed gas, driving them into underground garages, and detonating them to create a fuel-air concussion that would bring down the building. As I understand it, an enclosed place is ideal for maximum damage from a bomb like that, but obviously not essential. In fact, the cars found in the London plot three years ago were discovered parked on the street, just like the one found last night.

Update: Inevitably, this’ll be played off in some quarters as yet another keystone-cop amateur trying and pathetically failing to build a real terrorist bomb. Note well:

“It looked like someone tried to detonate it and we got to it in time,” a police source said. “This is a big deal. It has the makings of a real car bomb.”…

“The death toll could have been enormous,” a police source said. “It was a nice day and the Times Square area was completely packed.”

Update: I mentioned the proximity of the bomb to Viacom HQ — which owns Comedy Central and “South Park” — in an e-mail to a friend last night, but didn’t post it here since I figured the whole thing would be a false alarm. Turns out the NYPD is on the case:

Police in New York are investigating whether a car bomb in Times Square was targeted on the makers of South Park over a controversial depiction of the Prophet Muhammad.

The device, which failed to detonate, was left near the offices of Viacom, which owns the irreverent cartoon series.

Update: The NYPD is now denying that they’re investigating any links to the threats against Comedy Central. Meanwhile, an intriguing lead from Roggio:

A top Pakistani Taliban commander took credit for yesterday’s failed car bomb attack in New York City.

Qari Hussain Mehsud, the top bomb maker for the Movement of the Taliban in Pakistan, said he takes “fully responsibility for the recent attack in the USA.” Qari Hussain made the claim on an audiotape accompanied by images that was released on a YouTube website that calls itself the Tehreek-e-Taliban Pakistan News Channel.

The tape has yet to be verified, but US intelligence officials contacted by The Long War Journal believe it is legitimate. The Tehreek-e-Taliban Pakistan News Channel on YouTube was created on April 30. Officials believe it was created to announce the Times Square attack, and Qari Hussain’s statement was pre-recorded.

“This attack is a revenge for the great & valuable martyred leaders of mujahideen,” Qari Hussain said. He listed Baitullah Mehsud, the former leader of the Pakistani Taliban who was killed in a Predator strike in August 2009, and Abu Omar al Baghdadi, the former leader of al Qaeda Islamic State of Iraq who was killed by Iraqi forces in mid-April. And although he was not mentioned, an image of Abu Ayyub al Masri, the leader of al Qaeda in Iraq, was also displayed in the images accompanying the audiotape.

WaPo cites sources saying that an unknown “powder” was also found in the vehicle while reminding readers that Abdulmutallab had a powder-based bomb aboard Flight 253. If this thing really was a revenge attack for Baghdadi and al-Masri, they pulled it together awfully quickly: Those two were killed just 12 days ago. If, on the other hand, the Taliban had nothing to do with it and are simply trying to steal a little credit, why rush out a tape for a failed bombing attack? They would have been better off claiming that they blew up the BP rig or something; as improbable as that claim would have been, there are plenty of people who would have taken it seriously.

Update: A possible answer to the last question: Maybe Hussain and his media people aren’t in a position right now where they can get news from NYC to verify whether the attack succeeded. If this was in fact a Taliban op and the leadership knew it was scheduled for last night, they might have simply put out the tape this morning on the assumption that the bomb had gone off as planned. Or maybe they’re lying their asses off and trying to opportunistically piggyback on an attack that they actually had nothing to do with. Although if that’s the case, it raises the question of what attack they did have in mind when they made the tape. Hmmmm.

Update: Coincidence or not? Cops in Pittsburgh say they’ve found a bomb along the route of today’s marathon.

Police say the device was found in a small microwave oven on the sidewalk after the leaders had finished the course Sunday morning. Several blocks were cordoned off near the original finish line for the marathon and half-marathon.

The bomb squad used a robot to disable the device. The all-clear was given for the area shortly before 11 a.m. About 5,000 people took part in the full marathon.

Update: A promising lead from this afternoon’s NYPD presser:

Police and federal agents on Sunday were reviewing surveillance footage that shows a possible suspect in the failed Times Square car bombing, describing him as a white man in his 40s who was walking away from the area where the vehicle was parked, looking furtively over his shoulder and removing a layer of clothing, officials said…

Federal authorities said the incident appeared to be an isolated one, and that there was no evidence of an ongoing threat to the city.

Upon opening the gun locker found in the car, cops discovered eight bags of what could be fertilizer, which of course is what McVeigh used to bring down the Murrah building. There’s also this, which sounds like a crank call but who knows:

On Sunday, police and F.B.I. officials were also investigating a 911 call placed at around 4 a.m. on Sunday, several officials said. The caller, who one official said sounded intelligent, admonished the 911 dispatcher not to interrupt him until he was finished and then said there would be a massive explosion soon and the car in Times Square was only a diversion.

Kelly says there’s no evidence to substantiate the Taliban’s claim of responsibility. Stay tuned.

Update: WaPo’s got an interesting piece up debating whether this is likely jihadists at work or not. Evidently there’s been tons of chatter online lately about avenging the killings of Al Qaeda’s leaders in Iraq, but the description of the bomb really does make it sound amateurish. Turns out the powder found in the car is the sort of pyrotechnic stuff you find in fireworks, not something explosive like PETN. And the propane tanks were sealed rather than left open, which evidently makes it much harder to generate a big explosion. Then again, the 2007 London plot had jihadi fingerprints all over it and those bombs didn’t detonate either.

Update: The best evidence yet that this was the work of a bona fide amateur: They found 100 lbs. of fertilizer in the back, and … it’s non-explosive. What kind of moron bomber would go to the lengths this guy went to without making sure that the stuff he’s got actually goes boom?