Danish Prime Minister Mette Frederiksen was taken to the hospital with a minor whiplash injury after a man hit her in central Copenhagen, her office said.
Frederiksen is "safe but shaken" by Friday's incident, the office said, adding that her scheduled engagements on Saturday were cancelled.
Eyewitnesses told Danish media that the 46-year-old prime minister had been able to walk away from the scene.
Police quickly arrested a 39-year-old man in connection with the assault on Kultorvet square in the capital's historic centre. He later appeared in a pre-trial custody hearing in a Copenhagen district court.
The man denied that he had anything against Frederiksen, saying she was "a really good prime minister" and that he had been surprised to run into her on the street.
Police investigating the assault do not believe that the attack was politically motivated.
The Danish news agency Ritzau reported that the man was drunk and under the influence of other drugs at the time and that he was a Polish citizen who had been resident in Denmark for a long time.
Condemnation poured in from across Europe.
"Shocked to hear about the violence against my friend Prime Minister Mette Frederiksen of our ally Denmark. I strongly condemn all violence against our political leaders," NATO Secretary General Jens Stoltenberg wrote on the social media platform X.
European Commission President Ursula von der Leyen called it a "despicable act which goes against everything we believe and fight for in Europe," while French President Emmanuel Macron denounced it as "unacceptable" and wished the leader a quick recovery.
German Chancellor Olaf Scholz posted a get-well message on X. "Dear Mette, I wish you a speedy recovery," he said.
British Prime Minister Rishi Sunak posted on X: "Democracies must be free from intimidation and threats."
"I strongly condemn any form of violence against democratically elected leaders in our free societies," Finnish Prime Minister Petteri Orpo said.
"An attack on a democratically elected leader is also an attack on our democracy," wrote Swedish Prime Minister Ulf Kristersson on X.
The incident comes as the EU's 27 countries elect more than 700 members of the European Parliament during four days of voting that began on Thursday. Voters in Denmark go to the polls on Sunday.
There have been at least two attacks on politicians in Germany in the immediate run-up to the elections. And on May 15, Slovakian Prime Minister Robert Fico was shot and seriously injured.
