TSA has begun searching several planes in the US after British officials discovered a bomb on a Yemen-to-US cargo flight.  The bomb was disguised in a toner cartridge, and the UPS flight was due to land in Chicago today:

Investigators in the United Kingdom found a bomb disguised as a toner cartridge aboard a plane flying from Yemen to Chicago when it stopped in London on Thursday night – one reason for heightened concern at U.S. airports on Friday, a law-enforcement source with detailed knowledge of the investigation said.

Two UPS cargo planes at Philadelphia International Airport and another at Newark International Airport are being examined for questionable shipments, the company said. One of the planes at Philadelphia came from Paris, the other from Cologne, Germany, UPS said. The plane at Newark also arrived from Cologne.

These reports are preliminary, of course, but the Yemen connection strongly hints at al-Qaeda.  The network has tried to conduct a large-scale operation against the US for years, but usually target passenger services like normal commercial flights or subway systems.  They may have decided to test the cargo system to see whether they can penetrate it effectively — and if the bomb made it to the UK, they have at least managed to succeed on the first phase of a terrorist attack.

Assuming this story gets substantiated, it may put a big dent in international trade.  The vulnerability was always present in shipping on sea and in the air; six years ago, the lack of inspections at American ports became an issue in the presidential election.  If packages have to get opened before flights, even just from a few origination points, it will raise the cost of trade substantially for everyone — which is, of course, the entire motivation for targeting the cargo systems.

It’s a good thing that AQ “no longer poses a threat to the US,” isn’t it?

Update: At the same link as above, CNN now reports that New York City has dispatched its bomb squad to a UPS delivery truck with a suspected bomb on board.

Update II: CNN now updates at the same link that the toner cartridge had been “manipulated,” but that it tested negative for explosive material.  ABC News, meanwhile, headlines its coverage at the moment by saying “Authorities investigate mass bomb plot against US cargo.”  Stay tuned.

Update III: The package in the UK looks like an attempt to at least trigger a security response:

Test results for explosives were negative, one law enforcement official told the Associated Press, but officials remained concerned. The flight had been bound for Chicago but was at a British airport when the cartridge was spotted.

During a basic security screening process in the United Kingdom, officials found the suspicious item, according to a U.S. government official who spoke on condition of anonymity.

U.K. officials discovered that the toner cartridge had been manipulated and found wires attached to it and white powder.

That may be hoax, or it could just be incompetence by the terrorists.

Update IV: Fox confirms that officials are concerned over “several” suspicious packages, with destinations in Pennsylvania, Illinois, New Jersey, and New York. The two planes in Philadelphia being checked came from Paris and Cologne, Germany, according to the AP.

Update V: CBS reports that the Joint Terrorism Task Force wants to find 10-20 packages sent out of Sanna, Yemen. If that “white powder” sounds familiar, it should:

A Joint Terrorism Task Force source tells CBS News that investigators are looking for between 10-20 packages shipped out of the UPS office in Sanna, Yemen during the same time frame. According to the source, there were components inside the ink cartridge.

Authorities are looking for a small device in the packaging similar to the Detroit underwear bomber device.

That strengthens the potential AQ connection.

Update VI: CBS now reports that the Newark plane and two trucks in NYC have been cleared (same link as last update).

Update VII: CNN reports that the US believes this to be an al-Qaeda plot originating from the al-Awlaki network, and that they wanted to target synagogues:

U.S. officials believe that al Qaeda in the Arabian Peninsula was behind the plot that caused a security scare at English and American airports on Friday.

A Yemeni diplomat in Washington says the Yemeni government has opened a full investigation into a suspicious device that was shipped from the country to the East Midlands Airport in the United Kingdom. …

In the last 24 hours, security officials received a tip from an unnamed ally that packages coming from Yemen were destined for synagogues in Chicago, Illinois, according to information given to CNN contributor Fran Townsend.

British security officials are holding “a number of suspicious packages” pulled from cargo flights.

Update VIII:  In case it wasn’t obvious, the initial investigations resulted from a tip, not routine security processing, according to CNN (same link).