Terrorism alert level lowered

WASHINGTON -- After 11 days at orange, the national terrorism alert level was dropped one notch to yellow Friday after officials determined that the threat of imminent al-Qaida strikes had diminished.

The alert level was changed after various intelligence sources noted a modest decrease in terrorist threats. Officials were also worried about a possible attack on Memorial Day, which passed without incident.

"The lowering of the threat level is not a signal to government, law enforcement or citizens that the danger of a terrorist attack has passed," Homeland Security Secretary Tom Ridge said in a statement. "The U.S. intelligence community remains concerned that al-Qaida is attempting to exploit our weaknesses."

No domestic terrorist strikes were attempted during the relatively brief alert. Previous alerts lasted roughly a month.

Yellow indicates an elevated risk of terrorist attack, while the old level, orange, means a high risk.

Yellow is the middle level on a five-color scale. The lowest two levels, green and blue, and the highest, red, have not been used since the system was adopted in March 2002.

Homeland Security officials say the system serves as guidance for law enforcement authorities, businesses and the public on how likely a terrorist attack is at a given time.

The alert level was raised on May 20 after terrorists believed linked to al-Qaida struck in Saudi Arabia and Morocco. Seventy-five people were killed, including eight Americans.

At the time, Ridge said it was feared the incidents could mark the beginning of a wave of worldwide attacks that could include U.S. targets.

With the alert, government authorities and businesses stepped up security, particularly at Memorial Day gatherings. Lowering the alert level allows authorities to scale back some measures, a move favored by many local governments struggling with budget shortfalls.

The terror alert has been at orange four times since the system was put in place. No domestic attacks have occurred during any of the alerts.

While some have raised concerns that too many nonspecific alerts will desensitize the public, officials say they have little choice but to put them out in the face of very real threats. Homeland Security officials believe increased security accompanying the alerts deters would-be terrorists from striking.

U.S. officials suspect al-Qaida's top leaders coordinated the Morocco and Saudi Arabia attacks to demonstrate al-Qaida still is viable.

Many of those leaders are believed to be in Iran, although Osama bin Laden is thought to be in the remote border region between Afghanistan and Pakistan. Their activities, along with information gleaned from prisoner interrogations and intercepted communications, played a key role in raising the alert, U.S. counterterrorism officials said.