Donald Trump appeared to be shot in the ear as gunshots were fired at the former president at a rally in Pennsylvania.
Trump grabbed at the side of his face and blood spattered across his cheek as several popping sounds were heard, sending supporters running for safety.
The former president quickly pumped a fist at the crowd to show he was not severely injured, as Secret Service agents raced to the stage to hurry him away.
Trump's campaign said he was taken to hospital following the incident, but said he is 'fine', and 'thanks law enforcement and first responders for their quick action during this heinous act.'
The shooting unfolded as Trump addressed supporters at a rally in Butler, Pennsylvania, on Saturday afternoon.
Frantic scenes took hold as shots rang out, sending Trump supporters streaming out from the stands and away from the event.
Within seconds, Trump was put to the floor by several Secret Service agents as they protected him from the shooter.
Early reports indicate that around eight to 10 shots were fired, and the press pool said 'residual bangs' were heard after Trump hit the floor.
Trump stood up shortly after and pumped his fist at the crowd, leading to chants of 'USA' and 'Make America Great Again.'
He appeared to mouth the word 'fight' to supporters at the same moment.
There is no early information regarding who the shooter may have been or if any arrests have been made at the event.
Moments before he appeared to be hit, Trump was using a graphic at the rally to speak about illegal immigration.
Secret service encircled Trump within seconds of the shots being fired, and the agency said in a statement that the former president is 'safe.'
'The Secret Service has implemented protective measures and the former President is safe. This is now an active Secret Service investigation and further information will be released when available,' the statement read.
The extent of Trump's injuries are not clear, although he appeared to want to show his supporters that he was okay moments after being shot.
Trump's former Vice President Mike Pence was the first to issue remarks on the shooting, saying on X: 'Karen and I are praying for President Trump and urge every American to join us.'
A spokesperson for the ATF said agents from the bureau have been deployed to assist with the aftermath of the chaos.
The White House confirmed that President Biden was briefed on the shooting following the incident.
Although shots continued to be fired after Trump ducked, there are no early reports of any others injured at the rally.