Donald Trump has explained remarks that suggested Sweden had suffered a terrorist attack by saying they referred to something he saw on television.
The president had baffled people in Sweden with his comments, made at his campaign rally in Florida on Saturday night.
Mr Trump said: "You look at what's happening in Germany, 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. You look at what's happening in Brussels, you look at what's happening all over the world. Take a look at Nice, take a look at Paris."
The comment prompted a barrage of social media reaction, with hundreds of tweets, and a local newspaper published a list of events that happened on Friday that appeared to have no connections to any terror-like activity.
On Sunday, Mr Trump used Twitter to explain: "My statement as to what's happening in Sweden was in reference to a story that was broadcast on @FoxNews concerning immigrants & Sweden."
White House spokeswoman Sarah Huckabee Sanders said Mr Trump was talking about rising crime and recent incidents in general, not referring to a specific issue.
The president may be referring to a segment aired on Friday night in the US on the Fox News Channel show Tucker Carlson Tonight.
It reported that Sweden had accepted more than 160,000 asylum-seekers last year but only 500 of the migrants had found jobs in the country.
The report, which was illustrated with video of broken windows and fires, went on to say that a surge in gun violence and rape had followed the influx of immigrants.
Reacting to Mr Trump's original remarks, Sweden's foreign ministry spokeswoman Catarina Axelsson said the government was not aware of any "terror-linked major incidents".
Sweden's Security Police said it had no reason to change the terror threat level.
"Nothing has occurred which would cause us to raise that level," agency spokesman Karl Melin said.
Former Swedish foreign minister Carl Bildt tweeted: "Sweden? Terror attack? What has he been smoking? Questions abound."
Addressing Mr Trump, the Aftonbladet newspaper wrote: "This happened in Sweden Friday night, Mr President."
It listed in English some events that included a man being treated for severe burns, an avalanche warning and police chasing a drunken driver.
One Twitter user said: "After the terrible events #lastnightinSweden, IKEA have sold out of this" and posted a mock Ikea instruction manual on how to build a "Border Wall".
Sweden, which has a long reputation for welcoming refugees and migrants, had a record 163,000 asylum applications in 2015. The country has since cut back on the number it annually accepts.
Its most recent attack linked to extremism happened in the capital, Stockholm, in December 2010.
An Iraqi-born Swede detonated two explosive devices, including one that killed him but no-one else.
In the month he has been president, Mr Trump's remarks and those of his staff have fuelled numerous news media "fact checks" pointing out inaccuracies and falsehoods.
On the subject of terrorism, Trump counsellor Kellyanne Conway referred to a "Bowling Green Massacre" that never occurred.