U.S. officials lowered the national terror threat level Thursday, suggesting the possibility of a terrorist attack has eased somewhat.

A statement issued by Homeland Security Secretary Tom Ridge and Attorney General John Ashcroft said the terror threat level was being lowered from orange, signifying a "high" level of alert, back down to yellow, indicating an "elevated" risk of a terrorist attack.

The statement said the decision to lower the alert level was made as part of a continuous process of reviewing and analyzing intelligence information related to terrorist threats.

White House spokesman Ari Fleischer says another factor was the end of the Muslim hajj, the religious pilgrimage to Mecca.

"If there is any one area that I could point to, while there are many, one area certainly is the passage of time given the hajj," he said.

However, the Ridge-Ashcroft statement said the decision should not be read as a signal that the danger of a terrorist attack has passed. U.S. officials say that detained al-Qaida operatives have warned them that terrorists will wait to launch another attack until Americans are less vigilant.

The threat level was raised to orange, or "high," on February 7. At that time, U.S. officials said they had specific intelligence indicating the possibility of an attack. Orange is the second highest level on the five part alert scale that was devised in the wake of the September 11 terrorist attacks.

Raising the alert level prompted government and private industry to step up security measures and sent many Americans to their local supermarkets and hardware stores in search of emergency supplies recommended by the Homeland Security Department in case of an attack.