Republican presidential candidate Donald Trump on Wednesday said Iran may have been behind recent attempts to assassinate him and suggested that if he were president and another country threatened a U.S. presidential candidate, it risked being "blown to smithereens."

Trump made his remarks at a campaign event after U.S. intelligence officials briefed him a day earlier on “real and specific threats from Iran to assassinate him,” according to his campaign.

Federal authorities are probing assassination attempts targeting Trump at his Florida golf course in mid-September and at a rally in Pennsylvania in July. There has been no public suggestion by law enforcement agencies of involvement by Iran or any other foreign power in either incident.

“There have been two assassination attempts on my life that we know of, and they may or may not involve, but possibly do, Iran, but I don’t really know,” Trump said at an event a pipe-fittings plant in Mint Hill, North Carolina.

“We’ve been threatened very directly by Iran, and I think you have to let them know ... you do any attacks on former presidents or candidates for president, your country gets blown to smithereens,” he said.

Trump also questioned why Iran’s president, Masoud Pezeshkian, who is attending the United Nations General Assembly in New York, is being protected by U.S. law enforcement.

“We have the president of Iran in our country this week, we have large security forces guarding him, and yet they’re threatening our former president and the leading candidate to become the next president — certainly a strange set of circumstances,” said Trump, who faces Democrat Kamala Harris, the current vice president, in the Nov. 5 election.

Trump's campaign said he would return to Butler, Pennsylvania, the site of the first attempt on his life, for a campaign rally at the same venue on Oct. 5.

His stop in North Carolina was Trump's second visit to the state in less than a week, as polls show the race there to be tight. Harris held rallies in two cities there earlier this month.

Republicans in the state are reeling from the allegations that their candidate for governor, Mark Robinson, a top Trump ally, called himself a "Black NAZI" and proposed reviving slavery in anonymous comments posted on a pornography website.