U.S. issues rare global travel alert to citizens about terror attack threat

The United States has issued a global travel alert to U.S. citizens about the threat of a terrorist attack advising them to be extra cautious regarding their personal security over the holiday period, citing Sydney's "lone-wolf attack".

The alert is second of its kind. The only time America has issued such an alert was in August 2013, reported Stuff.co.nz.

The warning also said that the threat includes public venues, churches, schools among terrorists' targets and not just U.S. government facilities, said the State Department.

The citizens have been advised to enroll in the Department of State's Smart Traveler Enrollment Program (STEP).

According to reports, al Qaeda militants or its allies could target U.S. government or private American interests, said the alert.