A fighter from the Islamic State group carried out today's mass shooting inside a gay club in Orlando, Florida, an ISIS-linked media report said, quoting an unidentified source.
"The attack that targeted a nightclub for homosexuals in Orlando, Florida and that left more than 100 dead and wounded was carried out by an Islamic State fighter," it said in a terse statement quoting a "source".
Amaq, the ISIS-linked news agency, gave no further details.
US media reported that the gunman -- widely identified as 29-year-old Omar Mateen, an American citizen of Afghan descent -- had pledged allegiance to the jihadist group IS.
Fifty people were killed, in addition to the shooter, and 53 wounded in the worst mass shooting in US history, the mayor of Orlando Buddy Dyer said earlier today.
US officials were probing whether the suspect had radical Islamic "leanings".
US President Barack Obama said the FBI was investigating the killings "as an act of terrorism".
