Taxi drivers gather at La Rambla boulevard during a memorial for the victims of a terror attack on Aug. 19, 2017. Photo by Angel Garcia/ UPI | License Photo
Dec. 24 (UPI) -- The U.S. Department of State has warned American travelers of a potential terror attack in Barcelona, Spain, over the holidays.
The department issued the alert via Twitter Sunday for the La Rambla area through Christmas and New Year's Day.
Authorities have been warned there could be an attack in the Catalan capital with a bus or similar vehicle.
"Exercise heightened caution areas of vehicle movement, including buses, in the Las Ramblas area of Barcelona during Christmas and New Year's," the State Department's Bureau of Consular Affairs wrote on its Twitter account. "Terrorists may attack with little or no warning, targeting tourist locations, transportation hubs and other public areas."
Spanish authorities are now looking for a suspect identified as B.L., a 30-year-old man from Casablanca, Morocco. He has a bus driver's license and a police record in Spain for insulting a member of the Civil Guard at Malaga Airport in 2016.
In addition to looking for bus and minibus drivers, police are also monitoring car rental companies and will increase patrols.
The Spanish ministry set its terror alert to level 4, one below the most severe warning.
Spain has had its share of terror attacks, including the Aug. 28, 2017, attack in which a man drove a rental van into a crowd in La Rambla, and the March 2004 train bombing in Madrid that killed 193 and injured 1,700. That same day, terrorists in Cambrils, south of Barcelona, drove a vehicle into a crowd.