US issues global travel alert due to 'increased terrorist threats'

The United States issued a worldwide travel alert on Monday warning American citizens of "increased terrorist threats" in the wake of the Paris attacks.

"Current information suggests that ISIL (aka Daesh), Al-Qaeda, Boko Haram and other terrorist groups continue to plan terrorist attacks in multiple regions," said the State Department advisory, which cited recent attacks in Denmark, France, Mali, Nigeria and Turkey.

"US citizens should exercise vigilance when in public places or using transportation," it said, advising Americans to avoid large crowds or crowded places and to "exercise particular caution during the holiday season."