The US has issued a rare global travel alert for its citizens in response to "increased terrorist threats".
The state department said "current information" suggested the Islamic State group, al-Qaeda, Boko Haram and others continued "to plan terrorist attacks in multiple regions".
The alert, it said, will remain in place until 24 February 2016.
France, Russia, Mali and several other countries have seen deadly attacks in the past month.
The alert advises US citizens to "exercise vigilance when in public places or using transportation".
They are also advised to "be aware of immediate surroundings and avoid large crowds or crowded places.US issues rare global travel alert over terror threats - BBC News