The militant Islamic State (IS) group has claimed responsibility for what it said was its first attack on U.S. soil – a shooting at an anti-Muslim event in Texas during the weekend that exhibited cartoons mocking the Prophet Muhammad.
The IS said on May 5 that the two men who attacked the art exhibit in Texas were among the militant group's membership.
The gunman, Elton Simpson, and his roommate and accomplice Nadir Soofi, were killed by an off-duty police officer and tactical police ( SWAT) working security at the event in the Dallas suburb of Garland on May 3.
U.S. investigators said on May 4 that they had extensively investigated Simpson, who opened fire at the event.
U.S. authorities say Simpson was prosecuted in 2010 for lying about his intent to carry out Islamic extremist attacks in Somalia.
But U.S. officials said they did not know Simpson and Soofi were planning the May 3 attack.