The US State Department has issued an advisory for those living or traveling in Europe .
It warns of possible terrorist attack by al-Qaida or other extremist terrorist groups.
The advisory urges citizens to be extra alert but does not say that travel should cease.
The State Department alert advises hundreds of thousands of U.S. citizens living or traveling in Europe to take more precautions about their personal security.
New York Senator, Charles Schumer says because of new technology, authorities are able to pick up on hints of what terrorists may be planning.
Officials say terrorists may be plotting attacks in Europe with assault weapons on public places, along the lines of the deadly 2008 shooting rampage in Mumbai, India.
International traveler, Eric Glass says he relies on security and does not worry about terrorism, despite a travel alert for Europe.
Some experts say the warnings could still hurt a fragile European economy already hit hard by the debt crisis.
If you would like to read the alert from the State Department website click on the link