State Department issues 'worldwide' travel alert

The U.S. State Department issued a rare worldwide travel alert on Monday, warning American travelers about the widespread threats posed by members of the Islamic State or copycat bombers.

The alert said that there were increased terror threats from al-Qaeda, Boko Haram and ISIL, the term used by the federal government for the Islamic State in Iraq and the Levant, which has claimed responsibility for the Paris terrorist attacks. The alert also said people unaffiliated with the groups may be inspired by recent terrorist attacks in France, Nigeria, Denmark, Turkey and Mali.

The alert comes as millions of Americans prepare to travel for the Thanksgiving holiday, and organizers of major events like the Macy's Thanksgiving Day Parade bolster their security preparations.

"U.S. citizens should exercise vigilance when in public places or using transportation," the alert said. "Be aware of immediate surroundings and avoid large crowds or crowded places. Exercise particular caution during the holiday season and at holiday festivals or events."

The alerts from State are usually focused on travel to specific countries for specific reasons, such as terrorism threats in Afghanistan, crime threats in Honduras, Ebola outbreaks in Sierra Leone or earthquake aftershocks in Nepal. But Monday's warning was global, meaning American passengers were asked to be on alert for possible terrorist attacks wherever they are traveling.

The last time the State Department issued a similar worldwide alert was December 2014.