A "security threat" has closed the U.S. consular agency by a major tourist hotspot in Mexico and officials have been told to keep away “effective immediately,” following a recent explosion aboard a ferry nearby. The U.S. Embassy in Mexico took the decision to close services in the coastal resort town of Playa del Carmen on Wednesday night, issuing a statement on the alert that did not specifically state what the threat was. The move comes after the ferry that links the coastal town with Caribbean island Cozumel suffered two alarming incidents in recent weeks. While disembarking nearby, a ferry suffered a non-fatal explosion in February, while an explosive device was found on another ferry the next week. Both incidents are under investigation. At the time, the embassy only barred employees from taking the ferry. Neither representatives in Mexico City nor the State Department elaborated much further on why the new measures were taken. "We take our obligat