Orlando shooting: Democrat Hillary Clinton calls massacre 'an act of terror'

Democratic US presidential candidate Hillary Clinton called the shooting in Orlando, Florida, "an act of terror" that requires the nation to "redouble" efforts to stop similar attacks.

"To the LGBT community: please know that you have millions of allies across our country. I am one of them," Clinton said in a statement on Sunday.

A gunman killed 50 people at a packed gay nightclub in Orlando, Florida on Sunday and wounded 53 others before being killed by police in the worst mass shooting in US history.

The shooter was identified as Omar S. Mateen, a Florida resident who a senior FBI official said might have had leanings towards Islamic State militants. Officials called the rampage a "terrorism incident," but cautioned that the suspected Islamist connection required further investigation.