Explosives Bound for USA Discovered on Cargo Flights

Suspicious parcels discovered in airfreight shipments by authorities in the UK and United Arab Emirates prompted a terror alert in which UPS planes were grounded in Newark and Philadelphia.

Federal investigators were inspecting the contents of the grounded planes at Newark's Liberty airport and Philadelphia International based on concerns over a terrorist threat originating from Yemen.

The Yemen-based Al Qaeda in the Arabian Peninsula is suspected, and investigators are looking into whether the packages were part of a dry run for a future mail-bomb plot. A UAE official told the Associated Press late Friday that an "explosive device" in Dubai was found in a courier company's regional hub.

FedEx reported earlier that a suspicious package was found at its Dubai facility.

Another package, found on a UPS plane at East Midlands Airport in central England, contained what looked like a toner cartridge with white powder and wires coming out of it.

The Thursday night discoveries prompted U.S. authorities on Friday to sweep a UPS plane in Newark, N.J., two UPS planes in Philadelphia and two UPS trucks in New York City.

The planes in Philadelphia are still being investigated. The Newark flight and New York trucks have been cleared [snip].

Given the origin of the packages, Al Qaeda in the Arabian Peninsula "is at the top of the list" of suspects, a U.S. official told Fox News.

"Since two of the suspicious packages that were intercepted were addressed to religious institutions in Chicago, all churches, synagogues and mosques in the Chicago area should be vigilant for any unsolicited or unexpected packages, especially those originating from overseas locations," Chicago FBI spokesman Ross Rice said.

Federal law enforcement officials said the suspicious device that resembled a toner cartridge was removed from the a flight in a distribution center at East Midlands Airport in the U.K.

A crew member aboard a UPS plane arriving to Philadelphia from Paris later notified authorities on approach about a suspicious package. The crew member described a possible radiological component to the package, the incident report said. The two occupants safely exited the aircraft after landing in a remote area of the airport.

A second UPS plane was isolated near the UPS terminal at the Philadelphia airport before take off, the report said.

A third UPS plane, which arrived at Newark Liberty Airport from East Midlands in the U.K., was investigated, but UPS says it was cleared and proceeded on to Louisville, KY.

Two UPS trucks in Brooklyn and Queens, N.Y., were also investigated and cleared, officials said.

Law enforcement officials also are investigating a suspicious packages in Portland, Maine. No word on whether that package has any links to UPS or Yemen.

"As an additional safety measure, FedEx embargoed all shipments originating from Yemen," Maury Lane, spokesman for FedEx told Reuters.