Donald Trump has jumped on the mass shooting in Orlando to attack President Barack Obama and bolster support for a ban on Muslims entering the country.
In the aftermath of the worst mass shooting in recent US history, Trump took to Twitter to hit out at Obama for not using the words "radical Islamic terrorism".
"Is President Obama going to finally mention the words radical Islamic terrorism? If he doesn't he should immediately resign in disgrace," one Tweet said.
Another added: "Appreciate the congrats for being right on radical Islamic terrorism, I don't want congrats, I want toughness & vigilance. We must be smart."
Yet another said: "What has happened in Orlando is just the beginning. Our leadership is weak and ineffective. I called it and asked for the ban. Must be tough."
The opportunism by Trump prompted a slap down by former leader of the Labour party Ed Miliband.
Miliband said: ""Appreciate the congrats" says Trump. Can there be a more heinous, self-serving, disqualifying statement about the murder of 50 people?"
The shooting in the gay nightclub in Orlando, Florida, claimed the lives of 50 people, the city's mayor Buddy Dyer has said.
Obama said Americans were "united in grief, in outrage and resolve to defend our people" after "an act of terror and an act of hate".
The gunman was named as Omar Mateen by officials, who added the killings were likely to have been ideologically motivated.
Amaq news agency, affiliated with the Islamic State, said that an IS "fighter" had carried out the attack.
Prime Minister David Cameron said on Twitter: "I'm horrified by reports of the overnight shooting in Orlando. My thoughts are with the victims and their families."
And Hillary Clinton, who will be the Democrat nominee in the fight against Trump, released a statement echoing Obama's and labelling the attacks an act of terror and an act of hate, while calling for more gun control.
"This is a time to stand together and resolve to do everything we can to defend our communities and country."
It also emerged that the suspect legally purchased multiple guns in the past few days, according to the BBC.