Authorities say the killers are on the run.

An employee at the shopping centre told the Reuters news agency “many shots were fired”.

Reports have suggested there is more than one attacker.

No details have emerged on who was behind the shooting and no one has claimed responsibility.

“We believe we are dealing with a shooting rampage,” police said adding no one is in custody but they suspect “a terror attack”.

Police said they believed more than one shooter was involved, as witnesses had told officers there were three shooters with rifles.

German security sources told Reuters there were at least two shooters.

The police tweeted that a major operation is underway and advised people to avoid the area.

What we know so far

• As many as three assailants have opened fire in the Olympia-Einkaufszentrum shopping centre in Munich
• Local media report that as many as 6 may have been killed, though this is not confirmed
• Munich police are advising people stay in their homes and do not travel to busy areas such as the city centre, as the attackers have not been arrested
• Bus, train and tram traffic has been stopped
• The main Munich train station has been evacuated 
• A huge police operation is underway, including helicopters reportedly drafted in from the German border patrol 

• Munich Police say that eyewitnesses reports suggest three people with weapons near the Olympia Einkaufszentrum shopping centre. 
• They also reiterate their plea for people in Munich to remain in their homes or take shelter in nearby buildings. 

Munich Transport Authorities say they have halted service on multiple train, tram and bus lines and the German rail operator said the main railway station in Munich has been evacuated. (Euronews)