BUTLER, Pennsylvania, July 13 (Reuters) - Donald Trump was shot in the ear during a Saturday campaign rally, streaking the Republican presidential candidate's blood across his face and prompting his security agents to swarm him, before he emerged and pumped his fist in the air, mouthing the words "Fight! Fight! Fight!"

The shooter was dead, one rally attendee was killed and two other spectators were injured, the Secret Service said in a statement. The incident was being investigated as an assassination attempt, a source told Reuters.

When the shots rang out, Trump, 78, had just started his speech. He grabbed his right ear with his right hand, then brought his hand down to look at it before dropping to his knees behind the podium before Secret Service agents swarmed and covered him. He emerged about a minute later, his red "Make America Great Again" hat knocked off, and could be heard saying "Wait, wait," before the fist bump, then agents rushed him to a black SUV.

"I was shot with a bullet that pierced the upper part of my right ear," Trump said later on his Truth Social platform following the shooting in Butler, Pennsylvania, about 30 miles (50 km) north of Pittsburgh. "Much bleeding took place."

It was the first shooting of a U.S. president or major party candidate since the 1981 attempted assassination of Republican President Ronald Reagan.