Donald Trump has said his comment suggesting a terror attack had taken place in Sweden was referring to a Fox News report about immigration figures.
While alluding to past terror attacks in Europe, including in Brussels, Nice and Paris, Mr Trump told the crowd: “You look at what’s happening last night in Sweden.
“Sweden, who would believe this? Sweden. They took in large numbers. They’re having problems like they never thought possible.”
No such incident occurred in Sweden, and Trump has since tweeted a clarification, after the country's baffled government asked for an explanation.
He said: "My statement as to what's happening in Sweden was in reference to a story that was broadcast on @FoxNews concerning immigrants & Sweden.”
Fox News host Tucker Carlson presented a segment on Friday night that reported a surge in crime had followed the influx of immigrants in Sweden.
A White House spokeswoman told reporters on Sunday that Mr Trump had been referring generally to rising crime and not a specific incident in the Scandinavian country.
Mr Trump has been widely criticised for making the assertions with little or no evidence.
Carl Bildt, the country’s former prime minister, asked on Twitter: “Sweden? Terror attack? What has he been smoking? Questions abound.”
Sweden's US embassy also appeared to take a jab at the president on Sunday, retweeting Trump's justification and saying: "We look forward to informing the US administration about Swedish immigration and integration policies."
There was, in fact, no such massacre and Ms Conway later admitted her error.
