Secret Service: Two dead, including suspected shooter, at Trump rally

An attendee has died and two are critically injured after a shooting at former US president Donald Trump's rally in Pennsylvania, the US Secret Service says.

The suspected shooter has also died, US Secret Service spokesman Anthony Guglielmi said in a statement.

"A suspected shooter fired multiple shots toward the stage from an elevated position outside of the rally venue," Guglielmi said.

"U.S. Secret Service personnel neutralized the shooter, who is now deceased."

Agents had "quickly responded with protective measures" and Trump was safe, Guglielmi said.

"One spectator was killed, and two spectators were critically injured."

He said the the incident was under investigation and the Secret Service has notified the FBI.