Homeland Security Secretary Tom Ridge announced Friday that the terrorism threat level was being lowered from “orange,” or high, to “yellow,” or elevated, saying that an urgent threat had eased.
“I know we are all thankful that nothing happened,” Ridge said at a news conference in Washington.
Ridge said some government and private sector facilities would remain at a higher level of alert, although he declined to characterize their status as “orange,” saying that designation was reserved for nationwide alerts.
Airports, airlines to remain on high alert
Ridge would not identify the sectors or facilities that would remain on high alert, but a government official told The Associated Press that airports and airlines would be among them.
During heightened alerts, airports are asked to restrict parking near terminals if necessary, increase law enforcement patrols of terminals and perimeters, and conduct random checks of vehicles on airport roadways.
Two flights from Chicago were grounded because of security concerns Friday. One of the cases was determined not to be serious, but the other was considered credible because of specific information included in a telephoned bomb threat.
Sources told NBC News that seaports, financial markets, nuclear energy plants and landmarks deemed prime targets for a terrorist attack would also be among the areas that would remain on a heightened state of alert.
The conclusion of the holidays — and the large gatherings that go with them — played a role in the decision to lower the threat level, Ridge said.
“Although we’ve returned to yellow, we have not let our guard down,” he said. “Yellow still means that we are an elevated risk of attack, and we will maintain particular vigilance around some critical resources and locales.”
A senior U.S. official who spoke to NBC News on condition of anonymity was more specific, saying, “We are still not out of the weeds — we continue to be concerned.”
Reducing the threat level “does not rule out the possibility of seeing more attacks, to include possible attacks in the U.S.,” this official said.
Were attacks disrupted?
Ridge said he did not know yet whether the orange alert had actually disrupted a planned attack on U.S. soil. Past increases in security measures have served as deterrents, persuading terrorists to change their targets, he said, citing interviews with prisoners.
In particular, a group of operatives in Turkey decided not to target a U.S. diplomatic building there because security was too tight, Ridge said. In November, they hit a British consulate, instead.
“When we raise the security level, when you have more police, when you have frankly more security professionals involved in protecting communities and critical pieces of infrastructure, it is a deterrent. It does disrupt activity,” Ridge said.
Ridge raised the threat assessment to orange on Dec. 21, saying U.S. intelligence experts had detected “a substantial increase” in the volume of threatening communications among suspected terrorists, suggesting that an attack similar to the Sept. 11, 2001, strikes could be in the offing.
The system ranks threats by colors, starting with green at the bottom and followed by blue, yellow, orange and red as perceived dangers intensify. The warning level can be changed for the entire country or for specific regions and economic sectors.
Worries of an al-Qaida spoof
Some officials have worried that operatives of the al-Qaida terrorist network were deliberately trying to spoof U.S. and international intelligence networks aimed at uncovering terrorist threats by planting misinformation on lines of communications they believed were monitored.
A U.S. intelligence official told NBC News that the intelligence community’s job was being made more difficult by the rising level of chatter from “al-Qaida wannabes,” who were becoming a “larger part of the intelligence” universe. The threats are often circulated to call attention to specific organizations and boost morale of followers awaiting word of a real attack, the official said.
But officials said the amount and energy level of the threatening intelligence were too widespread for the current spate of reports to entirely be a disinformation campaign.
During the orange alert period, U.S. officials said they were focused on possible threats to the aviation system, particularly the threat of overseas flights being hijacked and on U.S. targets.
Security was raised to extraordinary levels over the last several weeks. In particular, several international flights were canceled and military helicopters patrolled during the large celebrations on New Year’s Eve in Las Vegas and at Times Square in New York.
The terror alert has been raised to orange several times since the color-coded alert system was put in place in early 2002 after the Sept. 11 attacks.
No attacks have taken place on U.S. soil during those orange alerts in the past.
NBC’s Pete Williams and Carl Rochelle in Washington and Robert Windrem in New York and The Associated Press contributed to this report.