The US Secret Service has had "more than one" conversation with Donald Trump's campaign about comments the Republican candidate made about gun rights, it has been reported.
Yesterday at a rally in North Carolina, Mr Trump said if the Democratic nominee Hillary Clinton got to pick her judges, "nothing you can do folks".
But he then added: "Although the Second Amendment people, maybe there is, I don't know."
Some critics believe Mr Trump was referring to gun violence against his rival.
CNN reported that the Secret Service had spoken to Mr Trump's campaign about his remarks on gun rights.
Mr Trump denied that, saying on Twitter that "no such conversation" had ever happened.
A government offical said the Secret Service never "formally" spoke to the Trump campaign about the comments.
Speaking at a rally in Des Moines, Iowa, Hillary Clinton said Mr Trump was inciting violence when he said gun rights supporters could stop her from winning.
"Words can have tremendous consequences," Mrs Clinton said.
Mr Trump's comments were the latest in a long line that showed he did not have the temperament to be president, she said.
"His casual cruelty to a Gold Star [military family], his casual suggestion that more countries should have nuclear weapons. And now his casual inciting of violence."
Mr Trump dismissed the claims, tweeting that he was trying to unify gun rights supporters to turn out to vote to defeat Mrs Clinton.