Authorities thwart terrorist attacks aimed at U.S.

Obama called the coordinated attacks a "credible terrorist threat" amid worldwide fears that al-Qaida was launching a major new campaign of assaults.

"The United States is not assuming that the attacks were disrupted and is remaining vigilant," Obama adviser John Brennan said at the White House.

One of the packages was found aboard a cargo plane in Dubai, the other in England. In the U.S., cargo planes were searched up and down the Eastern Seaboard, and an Emirates Airlines passenger jet was escorted down the coast to New York by American fighter jets.

No explosives were found aboard those planes, though the investigation was continuing on at least two.

Obama's sobering assessment, delivered from the White House podium, unfolded four days before national elections in which discussion of terrorism has played almost no role. The president went ahead with weekend campaign appearances.

The terrorist efforts "underscore the necessity of remaining vigilant against terrorism," the president said. While he said both packages that contained explosives originated in Yemen, he did not explicitly assign blame to al-Qaida, which is active in the Arab nation and long has made clear its goal of launching new attacks on the United States.

Authorities in Dubai intercepted one explosive device. The second package was aboard a plane searched in East Midlands, north of London, and officials said it contained a printer toner cartridge with wires and powder. Brennan said the devices were in packages about the size of a breadbox.

While the president didn't specifically accuse Yemen's al-Qaida branch, officials who spoke on condition of anonymity said they were increasingly certain that was the source. The same group was responsible for the attempted bombing of a U.S.-bound airliner last Christmas.

The radical U.S.-born Muslim cleric Anwar al-Awlaki, who now lives in hiding in Yemen, is believed to have helped inspire recent attacks including the Fort Hood shooting, the Times Square bombing attempt and the failed Detroit airliner bombing last Christmas Day.

Most of the officials spoke on condition of anonymity, citing the ongoing investigation.

Brennan later told reporters that the explosives "were in a form that was designed to try to carry out some type of attack," but he provided no further details.

"The forensic analysis is under way," he said, adding, "Clearly from the initial observation, the initial analysis that was done, the materials that were found in the device that was uncovered was intended to do harm."

Intelligence personnel had been monitoring a suspected plot for days, officials said. The packages in England and Dubai were discovered after a foreign intelligence service picked up information related to Yemen and passed it on to the U.S., one official said.

Confirmation that the package discovered in Dubai contained explosives came from an official United Arab Emirates security source.

U.S. intelligence officials warned last month that terrorists hoped to mail chemical and biological materials as part of an attack on America and other Western countries using the mail. The alert came in a Sept. 23 bulletin from the Department of Homeland Security and obtained by The Associated Press.

In the hours following the discoveries, Yemeni officials said they had launched a terrorism investigation, and Scotland Yard said its investigators were testing a number of additional items seized from the plane in East Midlands.

U.S. authorities conducted searches of aircraft in Philadelphia, Newark, N.J., and New York City.

"As a precaution, DHS has taken a number of steps to enhance security," the Homeland Security Department said in a statement. "Some of these security measures will be visible while others will not."

UPS said it was immediately suspending shipments out of Yemen.

Since the failed Christmas bombing of a Detroit-bound airliner, Yemen has been a focus for U.S. counterterrorism officials. Before that attack, the U.S. regarded al-Qaida's branch in Yemen as primarily a threat in the region, not to the United States.

The Yemen branch known as al-Qaida in the Arabian Peninsula has since become a leading source of terrorist propaganda and recruiting. Authorities believe about 300 al-Qaida members or cells operate in Yemen.

The Yemeni government has stepped up counterterrorism operations, with help from the U.S. military and intelligence officials. Mohammed Shayba, general-director of the state airline's cargo department, said the government is conducting an investigation.

"Those in charge are in constant meetings and they are investigating and taking the issue seriously," he told The Associated Press.

Shelly Katz, a spokeswoman with the Durham-Chapel Hill Jewish Federation, said the federation is aware of the threats made against their synagogues around the world, and always takes precautions. Katz said she wishes that they didn’t have to deal with these threats but understands that we live in a world that presents these dangers.

An administrator at Temple Beth Or in Raleigh said there is always extra precaution taken when packages coming into the synagogue. She said no special precautions were being taken in light of Friday's incident.