NEW YORK -- Former US President Donald Trump said on social media that he was shot at a rally in Butler in the US state of Pennsylvania on Saturday.

"I was shot with a bullet that pierced the upper part of my right ear," he said on his social media platform Truth Social.

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

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

In the post, Trump said one person was killed at the rally, and another badly injured, adding that "nothing is known at this time about the shooter, who is now dead."

"During former President Trump's campaign rally in Butler, Pennsylvania on the evening of July 13th at approximately 6:15 pm, a suspected shooter fired multiple shots toward the stage from an elevated position outside of the rally venue," the US Secret Service said in a press statement.

"US Secret Service personnel neutralized the shooter who is now deceased. US Secret Service quickly responded with protective measures and the former president is safe and being evaluated," the statement said.

"One spectator was killed, two spectators were critically injured. The incident is currently under investigation and the Secret Service has formally notified the Federal Bureau of Investigation," it added.

US President Joe Biden said on Saturday that he had been briefed on the shooting at Trump's rally.

"I'm grateful to hear that he's safe and doing well," Biden said on X. "I'm praying for him and his family and for all those who were at the rally, as we await further information."