Former US president Donald Trump was rushed off the stage at a rally in Butler, Pennsylvania of the United States on Saturday after what sounded like gunshots rang out through the crowd.

Video footage showed that Trump was making a speech when popping sounds rang out over the rally. Screams could be heard in the crowd, and Trump was swiftly escorted off the stage by Secret Service agents. Blood could be seen on the side of his head and his ear. 

"The former president is safe," Secret Service Spokesperson Anthony Guglielmi said on social media platform X.

"An incident occurred the evening of July 13 at a Trump rally in Pennsylvania. 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," he said.

US President Joe Biden, who is in Delaware for the weekend, has been briefed on the situation, according to media reports. "I have been briefed on the shooting at Donald Trump’s rally in Pennsylvania," he said. "I’m grateful to hear that he’s safe and doing well. I’m praying for him and his family and for all those who were at the rally, as we await further information."