Updated

President Trump on Sunday attempted to clarify his remark at a weekend rally that suggested a terror attack had taken place Friday night in Sweden.

“My statement as to what's happening in Sweden was in reference to a story that was broadcast on @FoxNews concerning immigrants & Sweden,” the president tweeted.

Friday night's edition of "Tucker Carlson Tonight" featured an interview with documentary filmmaker Ami Horowitz about a surge in violent crime in Sweden.

Some have traced the crime increase in Sweden to a surge in the number of refugees entering from Africa, Asia and the Middle East.

Trump said at a campaign-style rally Saturday outside Melbourne, Fla.: “We’ve got to keep our country safe. You look at what’s happening in Germany, you look at what’s happening last night in Sweden. Sweden, who would believe this?”

Trump has made securing the United States from outsiders, particularly radical Islamic terrorists, a major part of presidential campaign and now his administration.

The president's mention of Sweden along with Germany resulted in Trump critics saying he had mistakenly referred to a terror attack.

Among the recent terror attacks in Germany was a December 2016 incident in which a terrorist drove a truck through a Christmas market in Berlin, killing 12 people and injuring roughly 50 others. The Islamic State terror group took responsibility for the attack.

Trump’s comment at the rally Saturday follows White House special counselor to the president Kellyanne Conway mistakenly citing a “massacre” in Bowling Green, Ky.

Trump’s Sweden comment was questioned by Swedish officials, the news media and Chelsea Clinton, the daughter of Hillary Clinton, the 2016 Democratic presidential nominee whom Trump defeated.

Clinton tweeted: “What happened in Sweden Friday night? Did they catch the Bowling Green Massacre perpetrators?”

“Unclear to us what President Trump was referring to, have asked US officials for explanation,” the Swedish embassy in Washington tweeted.

Fox News producer Jennifer Bowman and the Associated Press contributed to this report.