Video footage has been released which shows a gunman on a roof opening fire at Donald Trump during a campaign rally.

Mr Trump was giving a speech to supporters in Butler, Pennsylvania when the incident occurred.

He was seen ducking to the ground clutching his ear as a series of shots rang out and people screamed in panic.

Mr Trump was escorted away by Secret Service agents, and it was revealed later that a bullet had pierced the upper part of his right ear.

Disclaimer: The video below contains scenes some viewers may find distressing

One person in the crowd was killed and two were critically injured by the gunman, who the FBI has identified as Thomas Matthew Crooks, a 20-year-old man from Pennsylvania.

The FBI says it is treating the incident as an assassination attempt.

The video was released by TMZ and has been verified by BBC News, who have shared it on their website here.

How has Donald Trump responded to the shooting?

Mr Trump has said he will remain “resilient” and “defiant” after being targeted in the assassination attempt.

Writing on his Truth Social platform, the former US president thanked people for their thoughts and prayers.

He added: “Our love goes out to the other victims and their families. We pray for the recovery of those who were wounded, and hold in our hearts the memory of the citizen who was so horribly killed.

“In this moment, it is more important than ever that we stand united, and show our true character as Americans, remaining strong and determined, and not allowing evil to win.

“I truly love our country, and love you all, and look forward to speaking to our great nation this week from Wisconsin. DJT”

World leaders have condemned the shooting, with current President Jo Biden calling the attack “sick”.

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Mr Biden spoke with Trump on Saturday evening (July 13), the White House said. 

Meanwhile, Prime Minister Sir Keir Starmer said he was "appalled by the shocking scenes".

He added: "Political violence in any form has no place in our societies and my thoughts are with all the victims of this attack."