Donald Trump has called for the bodyguards who protect Hillary Clinton to be disarmed because of her stance on gun control, saying "Let's see what happens to her".
The Republican presidential nominee was speaking at a rally in Miami, where he contrasted his supporters, who he said back police and want crime reduced, to Mrs Clinton, who he derided as someone who "lives behind walls and raises money from hedge funds".
"I think that her bodyguards should drop all weapons. They should disarm. I think they should disarm immediately, what do you think, yes?," he said.
"Take their guns away, she doesn't want guns. Take them, let's see what happens to her. Take their guns away, OK. It will be very dangerous."
Both candidates have been protected by the Secret Service for months, but Mr Trump's latest take on Mrs Clinton's security detail brought swift denunciations, particularly from Clinton allies.
"Tonight, Donald Trump once again alluded to violence against Hillary Clinton," said Elizabeth Shappell, spokeswoman for Correct The Record, a pro-Clinton media watchdog group.
"This is a truly deplorable comment that betrays our nation's most fundamental democratic values," Ms Shappell said in a statement.
Stuart Stevens, a Washington-based political consultant who worked on Republican Mitt Romney's 2012 presidential campaign, tweeted: "The Secret Service should investigate this threat."
Mr Trump made a similar comment about Mrs Clinton and her armed protection in May while accepting the endorsement of the National Rifle Association, when he said Mrs Clinton would end the US Constitution's Second Amendment, which guarantees the right to bear arms.
"Let's see how they feel walking around without their guns or their bodyguards," he told the gun lobby group, speaking about Ms Clinton and her Secret Service detail.
Mr Trump was criticised by opponents last month when he suggested that gun rights activists could act to stop Ms Clinton from nominating liberal US Supreme Court justices, a comment some interpreted as encouraging a political assassination.
"If she gets to pick her judges, nothing you can do folks," Mr Trump told a rally in North Carolina on 9 August.
"Although the Second Amendment people, maybe there is, I don't know," he continued.
Mrs Clinton has called for tighter access to guns, including universal background checks, but has never said she planned to get rid of the Second Amendment.