President Obama Says Packages Contained "Explosive Materials"

Packages found abroad addressed to U.S. addresses contained "explosive materials" according to President Obama (pictured). Discovery of the packages caused some cargo planes to be grounded Friday, and led to a day of heightened tensions.

In a statement from the White House, Obama said that the packages represented a "credible terrorist threat" to the U.S. al Qeada on the Arabian Peninsula is thought to be responsible for the packages, which had originated in Yemen.

CNN reports that authorities were searching for 13 packages that had been sent from Yemen. Some had been found, but others are still missing. Cargo planes landing in Philadelphia, and Newark were inspected, and six of the packages were found on board two UPS planes in Philadelphia. Authorities have said that the incident could be a "dry run" to gauge the level of security before conducting a terrorist attack.

At least one passenger plane en route to New York's JFK Airport which was reportedly carrying a package from Yemen was escorted by NORAD jets from Canada and the U.S. That plane landed without incident, but authorities said they were acting out of "an abundance of caution." In a statement released to the media about that flight, Emerates Airlines said "Emirates Flight EK201, which has ... landed at JFK, originated in Dubai not in Yemen, as reported in the U.S. media. More information will follow as soon as we have it. Emirates is co-operating fully with the US authorities."

The first packages were discovered Thursday night. One was described as a "toner cartridge" that had been tampered with and had wires attached. Authorities did not say if the possible dry run was for an attempt to get explosives onto planes and into the U.S., or to assess the practicality of shipping unassembled bomb components into the U.S.

FMI: www.fbi.gov, www.tsa.gov