A photo of Seattle's Space Needle was discovered on a computer file in Afghanistan, but no evidence of a specific Al Qaeda terror threat was found, officials said.

"Federal officials assured us that Washington state is not under any credible threat of any attack," Gov. Gary Locke said Wednesday.

Washington National Guard Gen. Tim Lowenberg said the picture was taken from some distance away and had little intelligence value.

Officials did not say where the picture was found. The Seattle Times reported Thursday it was among the documents discovered in a cave in Tora Bora, Al Qaeda's former stronghold.

Mayor Greg Nickels and Police Chief Gil Kerlikowske said the FBI informed them of the picture several days ago.

"The indications are there are no immediate or specific threats to Seattle," Nickels said Thursday on CBS' This Morning.

"But it sure is a reminder that there are people out there who want to do harm to our country and in particular to our city.

"If there are any specific threats or reasons to be concerned, we'll share that with the public," he added.

NBC News reported Wednesday that evidence indicated large hydroelectric dams in the state, such as the Grand Coulee Dam, might be Al Qaeda targets.

In the CBS interview, Nickels said the evidence also pointed to "some landmarks that no longer exist," including the Seattle Kingdome.

The news raised concerns in the state where Algerian Ahmed Ressam was arrested with a car trunk full of explosives as he arrived at Port Angeles by ferry from British Columbia in December 1999. His arrest prompted Seattle to cancel millenium celebrations at the Space Needle.

Ressam, who trained in Usama bin Laden-financed terrorist camps in Afghanistan, was convicted of plotting to blow up Los Angeles International Airport.