MUNICH - At least nine people are believed to have been killed in a shooting rampage in a Munich shopping centre on Friday that police described as a suspected terror attack, and three gunmen are still at large.

Police warned of an "acute terror" situation in the southern German city, which saw panicked shoppers fleeing the mall as armed police roamed the streets on the hunt for the attackers. "We suspect terrorism," a Munich police spokesman told AFP.

The shooting spree began before 1600 GMT at a McDonald's restaurant and continued on a nearby street before the gunmen moved into the OEZ shopping centre, a police spokeswoman said.

"There are several dead and injured," the spokeswoman said.

It is the third strike against civilian targets in Europe in just over a week, and follows an axe rampage by a teenager on a train in the same German state of Bavaria on Monday and the truck attack in the French city of Nice on July 14.

German news agency DPA quoted police as warning of an "acute terror situation" with three assailants at large armed with "long guns".

A video posted on social media appeared to show a man dressed in black walking away from the McDonald's while firing repeatedly on people as they fled. Munich's main train station has been evacuated and metro and bus transport in the city suspended on police orders.

Three gunmen were involved in the shooting, according to a police statement, citing witnesses.

Europe has been on alert for terrorism in the wake of a string of attacks including bombings in neighbouring France and Belgium.

The OEZ shopping centre, which opened in the 1970s near the city's Olympic stadium, was surrounded by armed police and emergency vehicles, while a helicopter buzzed overhead.

"There is a major police operation under way in the shopping centre," Munich police said on Twitter, urging people to avoid the area.

Emergency vehicles were seen in the streets outside, as shoppers rushed away from the mall, some carrying children in their arms.

"Attention - avoid the neighbourhood around the OEZ. Stay in your homes. Leave the street," the Munich police tweet said.

Germany has so far escaped the kind of large-scale jihadist attacks seen in France.

But the shooting comes just days after a teenage asylum seeker went on a rampage with an axe and a knife on a regional train near Wuerzburg, also in Bavaria on Monday, injuring five people, two of them critically.

One victim is still fighting for his life, the hospital treating him said Friday.

Germany's Interior Minister Thomas de Maiziere said the teenager was believed to be a "lone wolf" attacker who appeared to have been "inspired" by the Islamic State group but was not a member of the jihadist network. Authorities said he shouted "Allahu akbar" (God is greatest) three times as he ran through the carriage slashing passengers on the train near the southern city of Wuerzburg.

The attacker is believed to be either Afghan or Pakistani and investigators are still trying to determine his identity.

The train rampage triggered calls by politicians in Bavaria, of which Munich is the capital, to impose an upper limit on the number of refugees coming into the country -- many of them via the southern state.

The assailant had arrived as an unaccompanied minor in Germany in June 2015 and had been staying with a foster family in the region of the attack for the last two weeks.

A record 1.1 million migrants and refugees were let in to Germany last year, with Syrians making up the largest group followed by Afghans.

The mall shooting comes just eight days after a 31-year-old Mohamed Lahouaiej Bouhlel used a truck to mow down 84 people, including children, in the French Riviera city of Nice last week.