WATCH: Trump rushed off stage by Secret Service after gunshots fired at Pennsylvania rally

BUTLER, Pa. (AP) — The shooting at former President Donald Trump’s rally in Pennsylvania is being investigated as an attempted assassination of the former president and presumptive Republican nominee, law enforcement officials say.

LIVE UPDATES: Officials say Trump rally shooter was 20-year-old man from Pennsylvania

Trump’s campaign said in a statement that the former president was “fine” after the shooting in Butler, Pennsylvania. A local prosecutor said the suspected gunman and at least one attendee are dead.

“President Trump thanks law enforcement and first responders for their quick action during this heinous act,” spokesman Steven Cheung said in a statement. “He is fine and is being checked out at a local medical facility. More details will follow.”

The Secret Service said in a statement that “the former President is safe.”

Two officials spoke to The Associated Press on the condition of anonymity to discuss the ongoing investigation. They said the shooter was not an attendee at the rally and was killed by U.S. Secret Service agents.

Butler County district attorney Richard Goldinger said in a phone interview that the suspected gunman was dead and at least one rally attendee was killed.

Trump, the presumptive Republican nominee, was showing off a chart of border crossing numbers during his last rally before the Republican National Convention opens Monday when the apparent shots began.

As Trump was talking, a popping sound was heard. Trump said, “Oh,” and put his right hand up to his right ear as people in the stands behind him appeared to be shocked. Two more pops could be quickly heard and he crouched down.

READ MORE: 5 things to know about the Trump rally shooting

Someone could be heard saying near the microphone at Trump’s lectern, “Get down, get down, get down, get down!” as agents tackled the former president. They piled atop him to shield him with their bodies, as is their training protocol, as other agents took up positions on stage to search for the threat.

Screams were heard in the crowd of several thousand people. The bangs continued as agents tended to him on stage. He could be heard on the video saying at least twice, “Let me get my shoes, let me get my shoes,” with another voice heard saying, “I’ve got you sir.”

Trump got to his feet moments later and could be seen reaching with his right hand toward his face. There appeared to be blood on his face.

The crowd cheered as he got back up and pumped his fist.

His motorcade left the venue moments later. His condition was not immediately known.

WATCH: Trump rally in western Pennsylvania cut short by apparent gunshots

Police began vacating the fairgrounds shortly after Trump left the stage in what local officers described as a crime scene.

President Joe Biden was briefed on the incident, the White House said. He received an updated briefing from Kimberly Cheatle, the director of the United States Secretary Service, Homeland Security Secretary Alejandro Mayorkas, and White House homeland security adviser Liz Sherwood-Randall.

Trump’s eldest son, Donald Trump Jr., posted a photo on X of Trump, his fist raised and his face bloody in front of an American flag, with the words: “He’ll never stop fighting to Save America.”

North Dakota Gov. Doug Burgum, Florida Sen. Marco Rubio and Ohio Sen. JD Vance, the three men on Trump’s shortlist for vice president, all quickly sent out statements expressing concern for the former president, with Rubio sharing an image taken as Trump was escorted off stage with his fist in the air and a streak of blood on his face along with the words “God protected President Trump.”

Pennsylvania Gov. Josh Shapiro, a Democrat, said in a statement on X that he had been briefed on the situation and Pennsylvania state police were on hand at the rally site.

“Violence targeted at any political party or political leader is absolutely unacceptable. It has no place in Pennsylvania or the United States,” he said.