Former US President Donald Trump was targeted in an assassination attempt on Saturday at a rally in Pennsylvania, just days before he was to accept the Republican nomination for the third time.

A barrage of gunfire caused panic, and a bloodied Trump, who reported being shot in the ear, was quickly surrounded by Secret Service agents and escorted to his SUV, pumping his fist in a show of defiance. The Trump campaign announced that the presumptive GOP nominee was doing “fine” after the incident, which he said resulted in a bullet piercing the upper part of his right ear.

“I knew immediately that something was wrong when I heard a whizzing sound, shots, and immediately felt the bullet ripping through the skin. Much bleeding took place,” Trump wrote on his social media site. Early Sunday, the FBI identified Thomas Matthew Crooks, 20, of Bethel Park, Pennsylvania, as the individual involved in the assassination attempt. The investigation remains active and ongoing, according to the agency.

Authorities confirmed that one attendee was killed and two spectators were critically injured, all identified as men.

The Secret Service reported that they neutralized the suspected shooter, who had attacked from an elevated position outside the rally venue, a farm show in Butler, Pennsylvania, and confirmed that Trump was safe.

During a press conference late Saturday, the FBI stated they were not ready to release the identity of the shooter and had not yet identified a motive for the assassination attempt.

The attack was the most serious attempt to assassinate a president or presidential candidate since Ronald Reagan was shot in 1981. It drew renewed attention to concerns about political violence in a deeply polarized U.S., less than four months before the presidential election. The incident could impact the tenor and security measures at the Republican National Convention, which is set to begin Monday in Milwaukee. Organizers stated that the convention would proceed as planned.