COPENHAGEN (AFP/REUTERS) - An unidentified gunman killed at least one person and wounded three police officers after opening fire Saturday on a cultural centre in Copenhagen hosting a debate on Islam and free speech.

Swedish artist Lars Vilks - the author of controversial Prophet Muhammad cartoons that sparked worldwide protests in 2007 - was among those at the debate targeted by the gunman who then fled the scene.

.

Danish Prime Minister Helle Thorning-Schmidt described the assault as "a terrorist attack" as Danish televion showed the windows of the Krudttonden cultural centre pock-marked by multiple bullet holes.

Police released a photo of the suspect showing a man in a dark anorak and a maroon hat carrying a black bag. They described him as 25-30 years old, around 185cm tall, with an athletic build.

French ambassador to Denmark Francois Zimeray, who had been present at the debate but was not hurt, told AFP the shooting was an attempt to replicate the Charlie Hebdo killings in Paris.

"They shot from the outside (and) had the same intention as Charlie Hebdo, only they didn't manage to get in," he said by telephone from the venue.

"Intuitively I would say there were at least 50 gunshots, and the police here are saying 200," he told AFP.

"Bullets went through the doors and everyone threw themselves to the floor."

He said on Twitter that he was not harmed.

A Femen activist, Inna Shevshenko, said on Twitter that there were several dozen people in the room.

The gathering was billed as a debate on art and blasphemy, and the venue was a cafe at a cultural centre in a central part of Copenhagen.

A statement by Danish police said "an unidentified man died after having been hit by bullets" in the strike, and three officers were wounded in the shooting. The dead civilian man was reported to be 40 years old.

Police also said the Volkswagen Polo the suspected assailant fled the scene in was found abandoned around two hours after the attack.

After witness statements indicated there was just one attacker, police later said they were hunting for a lone gunman.

Specialists commenting on the attack in initial media reports said it was likely automatic rifles were used in the strike in order to fire as many rounds in a short period of time.

"Denmark has today been hit by a cynical act of violence. Everything leads us to believe that the shooting was a political attack and therefore a terrorist act," the Danish premier said in a statement.

The assault comes at a time of heightened security and rising fears of Islamist attacks, following Jan 7 and 9 incidents in Paris that left 17 people dead.

A series of anti-terror sweeps have been carried out across Europe since mid-January, resulting in the arrests of dozens of suspected Islamic militants and seizures of large stocks of weapons and explosives.

'BULLETS WENT THROUGH DOORS'

Those included Jan 17 raids in Belgium that thwarted what police called imminent "terrorist attacks to kill police officers on public roads and in police stations." Two suspects were killed fighting Belgian police in those sweeps.

Charlie Hebdo raised the ire of Islamist extremists by republishing cartoons by Vilks and other caricatures, and periodically satirising Islam on its own in later editions.

Vilks has received numerous death threats and has lived under constant protection by the Swedish police since 2010.

Two years ago, an American woman who called herself Jihad Jane was sentenced to 10 years in prison for plotting to kill him.

Sweden's security police said Swedish bodyguards were with Vilks at the time of the shooting.

Authorities in southern Sweden said they were helping Danish police. Sweden is joined to Denmark by bridge, and transit across is largely unchecked.

Concern of renewed attacks targeting symbols of press liberties and freedom of expression have been growing since the Charlie Hebdo strike, Reporters Without Borders secretary general Christophe Deloire told AFP after the Copenhagen assault.

"It's something that we feared after Charlie Hebdo. We see that ultra-radical groups are leading a war against freedom of expression, against the freedom to be irreverent about religion and against the simple freedom to debate them," Deloire said.

French Foreign Minister Laurent Fabius condemned what he called a "terrorist attack targeting a public meeting", saying in a statement that France "remains by the side of the Danish authorities and people in the fight against terrorism."

The French president's office said Interior Minister Bernard Cazeneuve was headed to the scene.