Washington DC, March 23 -- The US Department of State on Saturday (local time) issued a worldwide warning for its citizens, saying that Iranian supporters may attack US citizens.

The warning said that the citizens must follow the guidance in security alerts issued by the nearest US embassy or consulate.

"Worldwide Caution: The Department of State advises Americans worldwide, and especially in the Middle East, to exercise increased caution. Americans abroad should follow the guidance in security alerts issued by the nearest U.S. embassy or consulate. Periodic airspace closures may cause travel disruptions. U.S. diplomatic facilities, including outside the Middle East, have been targeted. Groups supportive of Iran may target other U.S. in...