Public figures have offered their condolences to people in Munich following the shopping centre shooting.
UK Foreign Secretary Boris Johnson issued a statement which said: "I am shocked and appalled by the terrible attack unfolding this evening in Munich, and the loss of life.
"My thoughts are with those injured and the families of those killed. We stand ready to assist our friends in Germany.
"Our travel advice to UK nationals in the area tonight is to stay indoors and follow the advice of the local authorities."
UK Labour leader Jeremy Corbyn tweeted: "Shocking news from Munich - my thoughts are with the people of the city at this time."
Leader of the Liberal Democrats Tim Farron tweeted: "My thoughts and prayers are with the people of Munich tonight. All of Britain stands with you."
US president Barack Obama said: "Our hearts go out to those who may have been injured. It's still an active situation and Germany is one of our closest allies so we are going to pledge all the support that they may need in dealing with these circumstances."
He said it was a "good reminder" that people's "way of life, our freedoms, our ability to go about our business every day" was dependent on law enforcement.
Charlie Flanagan, Irish Minister for Foreign Affairs and Trade, said he was "horrified" by the attack.
"Our thoughts are with the families and loved ones of anyone affected by this horrific event, and we extend our deep condolences to the German people.
"My department is monitoring the situation and is in close contact with the Irish Embassy in Berlin. At this time we are not aware of any Irish citizens having being caught up in this evening's incident.
"I urge any Irish citizens in the area to follow the German authorities' advice to avoid public areas and to stay indoors."
Shadow foreign secretary Emily Thornberry said: "Our heartfelt thoughts and sympathies are with the people of Munich, and we send our support to the German police, intelligence and emergency services who are dealing with these unfolding and tragic events.
"While it is unclear at this stage how many innocent people have been killed or injured, how many gunmen are involved, or what twisted motivation they hold, we can say one thing with certainty: anyone who tries to commit indiscriminate, mass murder against ordinary men, women and children going about their daily lives stands for nothing but evil.
"Our response cannot be to let them win by changing the way we live, or reacting ourselves with hatred and intolerance. We must stand defiant to protect our way of life, and we must take determined and unified action against anyone who wants to destroy it."
German president Joachim Gauck said: "I am deeply shocked by the murderous attack in Munich.
"My thoughts are with all the victims and all those who are grieving or fearing for a loved one. And I feel a bond with all those who are working to protect people and save lives."
Hillary Clinton tweeted: "Monitoring the horrific situation in Munich. We stand with our friends in Germany as they work to bring those responsible to justice."