U.S. issues travel alert for Europe

WASHINGTON, Oct. 3 (UPI) -- The U.S. State Department issued a travel alert for Americans visiting Europe Sunday after evidence surfaced that al-Qaida might be planning an attack.

The alert told Americans to be on their toes while in Europe because public transportation and tourist attractions could be potential targets

"Current information suggests that al-Qaida and affiliated organizations continue to plan terrorist attacks," the alert said. "European governments have taken action to guard against a terrorist attack and some have spoken publicly about the heightened threat conditions."

The alert was the result of recent reports that western intelligence agencies had gotten wind of a possible plot to unleash teams of gunmen to shoot up major European cities. A similar attack in Mumbai, India, two years ago resulted in around 160 deaths.

"U.S. military installations are taking prudent precautions," a senior U.S. official told CNN. "This is a serious situation."

The State Department urged Americans "to be aware of their surroundings" and to register their travel plans on the State Department's Web site.