MIAMI • The father of the shooter who terrorised a nightclub in Orlando, Florida, in June attended a campaign rally on Monday for Mrs Hillary Clinton, compelling her campaign to move quickly to distance itself from him.

The shooter's father, Mr Seddique Mateen, was spotted by a local television affiliate at the rally in Kissimmee, Florida, about 32km south of Orlando. He was just behind Mrs Clinton as she spoke.

On Tuesday morning, as news of his attendance set off an uproar on social media, Mrs Clinton's aides moved to play down Mr Mateen's presence. "The rally was a 3,000-person, open-door event," the campaign said. "This individual wasn't invited... and the campaign was unaware of his attendance until after the event."

Early in her remarks on Monday, Mrs Clinton touched on the Orlando shooting, during which Mr Mateen's son, Omar Mateen, killed 49 people at Pulse, a gay nightclub.

Omar Mateen was killed in a stand-off with the police. "I know many people... are still grieving," Mrs Clinton said of the victims' families. "I want them to know we will be with you."

Mr Mateen's presence was first noted by WPTV reporter Tory Dunnan, who was initially rebuffed for an interview but then was surprised to find Mr Mateen holding a pro-Clinton sign and asking to talk to the press. "Clinton is good for the United States, versus Donald Trump," Mr Mateen said in broken English. "I was invited by the Democratic Party; I'm a member."

Asked about his son, Mr Mateen said he wished "my son (had) joined the army and fought ISIS" instead.

NEW YORK TIMES, WASHINGTON POST