Elon Musk, the billionaire CEO of Tesla, said in a social media post on Saturday: "I fully endorse President Trump and hope for his rapid recovery."

Earlier, multiple shots rang out at Donald Trump's rally in Pennsylvania on Saturday, with the Republican presidential candidate grimacing and raising his right hand to his right ear as shots rang out, video footage showed.

Trump is "safe" after an incident Saturday at a rally in Pennsylvania, which saw him rushed off the stage after what sounded like possible shots were heard.

"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," Secret Service communications chief Anthony Guglielmi said on X.

The former president was rushed off stage by Secret Service agents after a series of loud bangs that sounded like possible gunshots were heard at the start of a campaign rally in Pennsylvania.

Trump was seen with blood on his right ear as he was surrounded by security agents, who rushed him off the stage as he pumped his first to the crowd.

The "former president is safe," the secret service said after Trump was bundled into an SUV and driven away.

"This is an active crime scene," secret service officers told reporters, ordering them out of the area.

"We saw a lot of people go down, looking confused. I heard the shots, it sounded like between firecrackers and a small caliber handgun," said John Yeykal from Franklin, Pennsylvania, who was attending his first Trump rally.