The agency will indefinitely continue a ban on air cargo coming from Yemen and, starting Monday, extend the ban to all air cargo coming from Somalia, according to Secretary Janet Napolitano.
A senior Obama administration official also said Monday he could not rule out the possibility that more parcel bombs might be mailed. "We have to assume that there may be others out there," said the official, who would discuss the security enviromment only on the condition he not be identified.
Another administration official said more cargo security requirements will be forthcoming.
On October 29, two bombs disguised as ink cartridges were found in cargo packages aboard a United Parcel Service plane in Great Britain and at a FedEx facility at an airport in Dubai in the United Arab Emirates. The packages were shipped from Yemen, and the terrorist group known as al-Qaida in the Arabian Peninsula has claimed responsibility for the plot. A terrorist group known as al-Shabaab, which operates out of Somalia, is described as having links to al-Qaida as well.
Earlier this year, al-Qaida in the Arabian Peninsula and al-Shabaab reportedly were beginning to work together, such as by swapping militant fighters.
The senior official acknowledged the U.S. government is worried about increased collaboration between the two groups. He said al-Shabaab has the intent to cause harm to the United States, adding that U.S. citizens have been known to travel to Somalia to receive training in terrorist tactics. But he said there have not been any suspicious packages known to have been mailed from Somalia.
Meanwhile, Napolitano said Yemen's cargo security procedures must be enhanced before lifting the ban on shipments.
Additionally, starting Monday, the Transportation Security Administration, an agency within Homeland Security, will prohibit toner and ink cartridges weighing more than 16 ounces from being brought aboard passenger aircraft in the United States or destined for the United States. This applies to both hand-carried and stowed luggage.
"This ban will also apply to certain inbound international air cargo shipments as well," Napolitano said.
According to DHS, no cargo packages that are deemed to be high-risk will be allowed on passenger aircraft.
"Further, all cargo identified as high risk will go through additional and enhanced screening," Napolitano said. "These measures also impact inbound international mail packages, which must be screened individually and certified to have come from an established postal shipper."
She added that the Obama administration is working with private cargo shipping companies to develop a system under which cargo manifests for flights to the United States are sent to the U.S. government before those flights get in the air.
"The threats of terrorism we face are serious and evolving, and these security measures reflect our commitment to using current intelligence to stay ahead of adversaries -- working closely with our international, federal, state, local and private sector partners every step of the way," Napolitano said. "We encourage our partners, as well as our citizens, to remain vigilant and report any suspicious activity to local law enforcement authorities."
Her announced security steps clearly represent the "new reality," said Brandon Fried, executive director of the Airforwarders Association, which represents the $17 billion air cargo industry. His industry trade group held many meetings with the TSA discussing new security measures, said Fried, who added, "Who knew that printer cartridges were going to be a high risk item?"
These rules are "just the beginning," he said. "They're plugging up all these gaps at the same time, and they're starting to pinpoint areas of concern-and this means the focus on the high-risk shipper and high-risk points of origin."
Air freight companies are going to be held much more accountable for examining specific packages, said Fried, who expressed hope that U.S. officials will work with other governments to devise a "harmonized set of [security] standards."
Maury Lane, a FedEx spokesman, said his company supports the government's security measures but declined to discuss the amount of cargo traffic it handles from Yemen or the economic impact of closing that route.
"We know more about our packages that are shipped on airplanes in most cases than airlines know about the passengers that are flying on airplanes," Lane said about FedEx's own screening procedures. "We have extensive measures in place and we are always enhancing our capabilities, but our first priority must always be to focus on tactics that are effective," he added.
Sara Sorcher contributed to this report.