One man has died after a gunman opened fire on a cafe in Copenhagen, which was hosting a freedom of speech debate.
Three policemen were also injured in the shooting at the debate organised by Swedish artist Lars Vilks, who has faced numerous threats for caricaturing the Prophet Mohammed.
The gunman shot through the windows of the Krudttoenden cafe, which media reports said were riddled with some 30 bullet holes.
Helle Merete Brix, one of the organisers of the event, said Mr Vilks was present at the event but not injured.
She said: "I saw a masked man running past. I clearly consider this as an attack on Lars Vilks."
Police were looking for the perpetrators, who they said drove away in a dark Volkswagen Polo after the shooting, which took place shortly before 4pm local time.
Police said the victim was a 40-year-old man inside the cafe attending the event. He has not yet been identified.
Niels Ivar Larsen, one of the speakers at the event, said: "I heard someone firing with an automatic weapons and someone shouting. Police returned the fire and I hid behind the bar. I felt surreal, like in a movie."
Ms Brix said she was ushered away with Mr Vilks by one of the police guards he gets whenever he is in Denmark.
The cafe in northern Copenhagen, known for its jazz concerts, was hosting an event titled "Art, blasphemy and the freedom of expression" when the shots were fired.
Francois Zimeray, the French ambassador to Denmark who was at the conference, tweeted that he was "still alive".
Mr Vilks, 68, has faced several attempted attacks and death threats after he depicted the Prophet Mohammed as a dog in 2007.
A US woman was jailed for 10 years in 2014 for a plot to kill Mr Vilks. In 2010, two brothers tried to burn down his house in southern Sweden and were imprisoned for attempted arson.
After Islamic militants attacked the Charlie Hebdo satirical magazine in Paris last month, killing 12 people, Mr Vilks said that even fewer organisations were inviting him to give lectures amid increased security concerns.
Mr Vilks also said he thought Sweden's SAPO security service, which deploys bodyguards to protect him, would step up the security around him.
"This will create fear among people on a whole different level than we're used to," he said. "Charlie Hebdo was a small oasis. Not many dared do what they did."