Former US President Donald Trump survives 'assassination attempt'

Donald Trump has been hit in the ear in an assassination attempt by a gunman at a campaign rally, in a chaotic and shocking incident set to supercharge political tensions ahead of the polarising US presidential election.

The 78-year-old former president was rushed off stage on Saturday with blood streaked across his face after the shooting in Butler, Pennsylvania, while the shooter and a bystander were killed and two spectators critically injured.

The Republican candidate raised a defiant fist to the crowd as he was bundled away to safety, and said afterwards: "I was shot with a bullet that pierced the upper part of my right ear."

President Joe Biden, who is set to face Trump in November's deeply polarised election, said the incident was "sick" and added that there was "no place in America for this kind of violence."

Biden later spoke to Trump, the White House said.

Unconfirmed images appeared to show the assailant's body lying on the sloping roof of a low building from where he had fired, plunging the rally filled with Trump supporters into screams and panic.

The FBI has identified the shooter as 20-year-old Thomas Matthew Crooks of Pennsylvania, US media reported early Sunday.

"The FBI has identified Thomas Matthew Crooks, 20, of Bethel Park, Pennsylvania, as the subject involved in the assassination attempt of former President Donald Trump on July 13, in Butler, Pennsylvania," the FBI said in a statement quoted by NBC and CBS.

The shooter was believed to be working alone, but law enforcement officials said they would not release any details yet.

After multiple witnesses said they saw the gunman before the shooting and alerted authorities, Butler police said they had "responded to a number of reports of suspicious activity" but gave no further details.

'Ripping through the skin'

Trump, wearing a red "Make America Great Again" cap, had just started speaking at his final rally before the Republican National Convention when multiple bangs ran out.

He grimaced and clutched his ear, with blood visible on his ear and cheek, then ducked to the floor as Secret Service agents swarmed onto the podium, surrounding him and escorting him roughly off the stage to a nearby vehicle.

"It is incredible that such an act can take place in our Country," Trump said on his Truth Social network hours later, in remarks sure to stoke the political hostility already engulfing the United States.

"I knew immediately that something was wrong in that I heard a whizzing sound, shots, and immediately felt the bullet ripping through the skin," Trump said.

"Much bleeding took place, so I realized then what was happening."

The US Secret Service said in a statement that the suspected shooter "fired multiple shots toward the stage from an elevated position outside the rally" before being "neutralized" by agents.

Police confirmed that a male spectator was killed and two critically injured, all of them male adults.

Biden cut short a weekend trip to his Delaware beach house to return to Washington. He will receive an updated briefing from security officials on Sunday morning, the White House said.

The attack has already stoked political tensions, with some Republicans pointing the finger at Biden and right-wing conspiracy theories flooding social media.

Possible Trump vice presidential pick J.D. Vance said Biden's "rhetoric" had "led directly" to the Trump attack.

Trump's campaign said he would still attend the Republican National Convention in Milwaukee after he was reported to have had a precautionary hospital checkup.

Screams and panic

But the convention will now be dominated by the shooting at the rally, which descended into panic with screams and shouts ringing out after the gunshots.

"Let me get my shoes," Trump was heard saying on the microphone, as security agents helped him back to his feet.

He turned back to the crowd and repeatedly raised his fist, as well as mouthing words that weren't immediately discernible, in what instantly became an iconic image.

Agents bundled the tycoon into an SUV, as he once more shook his fist.

"We saw a lot of people go down, looking confused. I heard the shots," said John Yeykal from Franklin, Pennsylvania, who was attending his first Trump rally.

US political figures including former presidents Barack Obama and Bill Clinton lined up to condemn the attack and say there was no place for violence in politics.

Billionaire Elon Musk meanwhile reacted by quickly endorsing Trump.

The United States has a history of political violence, and presidents, former presidents and candidates have tight security.

President John F. Kennedy was assassinated in 1963 while riding in his motorcade, and his brother Bobby Kennedy was shot dead in 1968. President Ronald Reagan survived an assassination attempt in 1981.