Gunmen last night attacked a busy shopping mall in the German city of Munich, spraying bullets as people fled in horror for safety from what police said was a terrorist attack.

Police said at least eight people had been killed and the attackers were still at large, CNN reports.

They told the public to get off the streets as the city -- Germany's third biggest -- went into lockdown, with transport halted and highways sealed off.

There was no immediate claim of responsibility but supporters of Islamic State celebrated the rampage on social media.

One witness told CNN that she heard one attacker shout “Allahu Akbar” before he began shooting.

"Thank God, may God bring prosperity to our Islamic State men," read one tweet.

"The Islamic state is expanding in Europe," read another.

Daily Mail reported quoting witnesses that one gunman screamed 'I'm German' and 'f*** foreigners' before shooting.

As special forces rushed to the scene, some people remained holed up in the Olympia shopping centre.

"Many shots were fired, I can't say how many but it's been a lot," said a shop worker hiding in a store room inside the mall. The woman, who asked not to be identified, said she had seen a shooting victim on the floor who appeared to be dead or dying.

A worker at a different shop, Harun Balta, said: "We are still stuck inside the mall without any information, we're waiting for the police to rescue us."

It was the third major act of violence against civilians in Western Europe in eight days. Previous attacks in France and Germany were claimed by the Islamic State militant group.

Munich police spokeswoman said eight people were killed and an undetermined number wounded. No suspects had been arrested yet, she said.

Police evacuates people from a shopping mall in Munich yesterday following shootings that killed at least 8 people and wounding several. Photo: AFP

"We believe there was more than one perpetrator. The first reports came at 6:00pm (1700 GMT), the shooting apparently began at a McDonald's in the shopping centre. There are still people in the shopping centre. We are trying to get the people out and take care of them," the spokeswoman said.

Munich police said on Facebook that witnesses reported three different gunmen armed with rifles.

A video posted online -- whose authenticity could not be confirmed -- showed a man dressed in black outside a McDonalds by the roadside, drawing a handgun and shooting towards members of the public.

Police said witnesses had seen shooting both inside the mall and on nearby streets.

The shopping centre is next to the Munich Olympic stadium, where the Palestinian militant group Black September took 11 Israeli athletes hostage and eventually killed them during the 1972 Olympic Games.

Munich's main railway station was also evacuated. Bavarian broadcaster BR said police had also sealed off many highways north of Munich had been shut down and people were told to leave them.

A video grab posted on The Daily Mail online purportedly showing one of the shooters (circled in red) firing at people outside the mall. Photo: Mail Online

US President Barack Obama has pledged support for the German nation in wake of the attack.

Speaking at a White House meeting he said: “We don't yet know exactly what's happening there, but obviously our hearts go out to those who may have been injured.

“We are going to pledge all the support they may need.”

Friday's attack took place a week after a 17-year-old asylum-seeker wounded passengers on a German train in an axe rampage.

Bavarian police shot dead the teenager after he wounded four people from Hong Kong on the train and injured a local resident while fleeing.

German Justice Minister Heiko Maas told Bild newspaper's Friday edition before the mall attack that there was "no reason to panic but it's clear that Germany remains a possible target".

The incidents in Germany follow an attack in Nice, France, on Bastille Day in which a Tunisian drove a truck into crowds, killing 84. Islamic State also claimed responsibility for that attack.

Yesterday was also the five-year anniversary of the massacre by Anders Behring Breivik in Norway. Breivik is a hero for far-right extremists in Europe and America.

The Munich assault was also reminiscent of Islamist militant attacks in a shopping mall in Nairobi, Kenya, in September 2013 and in Mumbai, India, in November 2008.