Local and federal law enforcement agents stand guard at New York City's Penn Station as people line up to board a train Jan. 30, 2014. John Moore/Getty Images

The U.S. State Department released a worldwide travel alert Monday evening, advising U.S. citizens about “possible risks of travel due to increased terrorist threats,” according to its website. The travel alert expires Feb. 24.

“Current information suggests that ISIL, al-Qa’ida, Boko Haram and other terrorist groups continue to plan terrorist attacks in multiple regions. These attacks may employ a wide variety of tactics, using conventional and non-conventional weapons and targeting both official and private interests,” the alert stated.

The State Department advised citizens to exercise vigilance when in public places or using transportation, to be aware of immediate surroundings and to avoid large crowds or crowed places. The alert further stated that U.S. citizens should monitor media and local information sources and factor updated information into personal travel plans and activities.