Omar Mateen, who perpetrated Sunday’s attack at a gay nightclub in Orlando, killing more than 50 persons, and injuring dozens others, pledged allegiance to the Islamic State (IS) during a 911 call he made during the incident.
The U.S. has issued a warning to American citizens visiting Europe this summer to be on the alert for terrorism risks. Targets could include major sporting events and tourist sites, restaurants, commercial centers and transportation, says the State Department.