The US Department of State issued a worldwide travel alert on Monday, warning travelers of the potential risks of terrorism posed by the Islamic State, Al-Qaeda, Boko Haram, and other unaffiliated individuals inspired by the groups.

The alert referenced previous threats made against "large sporting events, theaters, open markets, and aviation services" and cited attacks in France, Nigeria, Denmark, Turkey, and Mali during the past year, as well as the downed Russian airliner over Egypt.

Travel Alert: Authorities believe likelihood of terror attacks will continue as ISIL/Da’esh return from Syria/ Iraq. https://t.co/Ebm8Ny3Bom — Travel - State Dept (@TravelGov) November 23, 2015

Encouraging US citizens to "exercise vigilance," the State Department stressed that the holiday season and holiday-related festivities would be targets, saying citizens should "follow the instructions of local authorities" and follow updates in the media when planning to travel, prepare for additional security screenings, to stay in touch with family in case of an emergency, and register with the department’s Smart Traveler Enrollment Program (STEP).

CBS News Correspondent Margaret Brennan says this is the first worldwide travel alert since December 2014.

.@StateDept issued a worldwide travel alert - 1st time since Dec 2014 - urging Americans to be extra vigilant given increased terror threats — margaret brennan (@margbrennan) November 23, 2015

The travel alert expires on February 24, 2016.