Fifty killed in Florida nightclub shooting. It is the worst mass shooting in U.S. history which authorities described as a possible act of terrorism.
Police killed the shooter, who was identified as Omar S. Mateen, a Florida resident, Unian wrote.
A top U.S. congressman said Mateen may have pledged allegiance to the Islamic State militant group.
U.S. officials cautioned, however, that they had no immediate evidence of any direct connection with Islamic State or any other foreign extremist group.