The United States has issued a worldwide 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 February 24 next year. 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".