Police stand beside a damaged truck which ran into crowded Christmas market in Berlin. Credit:AP Television pictures from Berlin showed Christmas decorations protruding from the smashed windscreen of the black truck, which came to rest amid the small wooden stalls that make up the "Christkindlmarkt". Police cars and ambulances converged on the scene, and officers with machine guns guarded the area. The initial death toll stood at nine, but German police later revised that up to 12. A further 48 people were in hospital, some with serious injuries. Police arrested the suspected driver of the truck shortly after the crash, while a passenger in the truck had died, Berlin police spokesman Thomas Neuendorf said. The suspect was arrested a few hundred meters from the scene on the basis of descriptions from witnesses.

Firefighters load an injured person into an ambulance after a truck ran into a crowded Christmas market. Credit:AP Berlin police said on Twitter they were investigating leads that the truck had been stolen from a construction site in Poland. German media cited local security sources as saying that there was evidence suggesting the arrested suspect was from Afghanistan or Pakistan, and had entered Germany in February as a refugee. A police officer stands guard after a truck ran into a crowded Christmas market in Berlin. Credit:AP The crash occurred at what would have been one of the most crowded times for the market, when adults and children would be gathering in the traditional cluster of wooden huts that sell food and Christmas goods.

The market is situated near the fashionable avenue Kurfuerstendamm, and at the foot of the ruined Kaiser Wilhelm memorial church that was kept as a ruin after World War II. Police guard a Christmas market in Berlin, after a truck ploughed into the crowd. Credit:AP Australian woman Trisha O'Neill was in the square at the time, and described seeing "blood and bodies everywhere". The 24-year-old Brisbane woman, who moved to Germany in September, was sitting nearby drinking gluhwein with friends when the truck crashed into the square. Emergency services attend the scene, after a truck ran into crowds at a Christmas market in Berlin. Credit:AP

"I just saw this huge black truck speeding through the markets crushing so many people and then all the lights went out and everything was destroyed," she told the ABC. "I could hear screaming and then we all froze. Then suddenly people started to move and lift all the wreckage off people, trying to help whoever was there." Ms O'Neill said she burst into tears when she saw how many people, including children, were laying on the ground. "I never thought I would see something like this in my life," she said. "I'm shaking and scared. It all just happened so fast."

The truck belongs to a Polish trucking company, its owner Ariel Zurawski told Poland's TVN 24 broadcaster, adding that its driver had been transporting steel to Berlin and had not been reachable since 4pm, local time. The Berliner Morgenpost newspaper reported that up to 50 people were injured. "I heard a big noise and then I moved on the Christmas market and saw much chaos ... many injured people," Jan Hollitzer, deputy editor in chief of Berliner Morgenpost, told CNN. "It was really traumatic."

Emma Rushton, a tourist visiting Berlin, told CNN the truck seemed to be travelling at about 65km/h. Asked how many were injured, she said that as she walked back to her hotel, she saw at least 10 people injured. Julian Reichelt, editor in chief of Bild in Berlin, said that there was currently a massive security operation under way. The incident evoked memories of an attack in France in July, when Tunisian-born Mohamed Lahouaiej Bouhlel drove a 19-tonne truck along the beach front, mowing down people who had gathered to watch the fireworks on Bastille Day, killing 86 people.

Police shot the driver dead in the Nice attack, which was claimed by Islamic State. "The scene certainly looks like a reminder of what we have seen in Nice," Reichelt said of the situation in Berlin. Berlin Mayor Michael Mueller said it was "a shock for us all." "In these times, it's truly difficult to experience something like our friends in other cities have experienced in recent months or years," he said. German Chancellor Angela Merkel was being briefed on the incident by Interior Minister Thomas de Maiziere and the mayor of Berlin, a government spokesman said.

"We mourn for the dead and hope that the many injured can be helped," Steffen Seibert, Merkel's chief spokesman, said in a Twitter statement. German police urged people in Berlin to stay at home to keep rescue routes to Breitscheidplatz free. There were no indications of "further dangerous situations in the city", police said. US President-elect Donald Trump condemned what he called an attack, linking it to "Islamist terrorists". It was not immediately clear whether any Australians were caught up in the incident.

The Department of Foreign Affairs advised Australian travellers to avoid the market area in Berlin where the crash occurred, but the overall level of advice for Germany remained unchanged. Travellers there are advised to exercise normal safety precautions and be aware of the increased threat of terrorism. Prime Minister Malcolm Turnbull extended condolences to the families of those killed, and said he had been in touch with Australia's ambassador Germany and the Australian Federal Police following the crash. "We are very attentive to events internationally to ensure that we learn from them and make sure that we put measures in place to anticipate similar occurrences here," he said on Tuesday. Anyone concerned about the welfare of Australians in Berlin can call the department on 1300 555 135 or the embassy in Berlin on 03 0880 0880.

Reuters, Bloomberg, Fairfax Media