Berlin - A lorry ploughed into a busy Christmas market in central Berlin on Monday, killing at least nine people and hurting 50 more in what police said was a possible terror attack.
Ambulances and heavily armed officers rushed to the area after the driver mounted the pavement of the market in a square popular with tourists, in scenes reminiscent of July's deadly truck attack in the French city of Nice.
"A man who was apparently driving the truck was detained," a police spokeswoman told AFP. "The person riding in the vehicle is dead." As witnesses described scenes of panic and carnage, police said at least nine were killed and 50 others were injured - four of them seriously - in the incident which comes less than a week before Christmas.
"We are investigating whether it was a terror attack but do not yet know what was behind it," a police spokesman said.
Authorities said there was no indication of "further dangerous situations in the city near Breitscheidplatz", where the suspected attack took place.
Police added they had no indications as yet to the nationality or age of the arrested man.
Germany Chancellor Angela Merkel reacted quickly to the tragedy, with spokesman Steffen Seibert tweeting: "We mourn the dead and hope that the many people injured can be helped".
Traditional Christmas markets are popular in cities and towns throughout Germany and have frequently been mentioned by security services as potentially vulnerable to attacks.
"It's awful. We were in Berlin for Christmas", said American tourist Kathy Forbes. "We also thought it would be safer than Paris." Australian Trisha O'Neill told the Australian Broadcasting Corporation she was only metres from where the truck smashed into the crowded market.
"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.
"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." O'Neill added that there was "blood and bodies everywhere".
Europe has been on high alert for most of 2016, with terror attacks striking Paris and Brussels, while Germany has been hit by several assaults claimed by the Islamic State group and carried out by asylum-seekers.
An axe rampage on a train in the southern state of Bavaria in July injured five people, and a suicide bombing wounded 15 people in the same state six days later.
In another case, a 16-year-old German-Moroccan girl in February stabbed a police officer in the neck with a kitchen knife, wounding him badly, allegedly on IS orders.
The arrival of 890,000 refugees last year has polarised Germany and misgivings run particularly deep in the ex-communist east, even more so since IS-linked attacks in July carried out by asylum-seekers.
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The attack in Berlin also comes five months after Tunisian extremist Mohamed Lahouaiej Bouhlel ploughed a 19-tonne truck into a crowd on the Nice seafront, killing 86 people.
In response to the suspected attack in Berlin, French President Francois Hollande said, "The French share in the mourning of the Germans in the face of this tragedy that has hit all of Europe." The Nice bloodshed - as people were watching a fireworks display on the Bastille Day public holiday on July 14 - further traumatised a France already reeling from a series of jihadist attacks.
Six people have been charged so far over alleged links to the 31-year-old killer but investigators have yet to prove that any of them knew what he was planning.
IS moved quickly after the attack to claim Bouhlel as one of its followers. Investigators said he suffered from depression and appeared to have become radicalised very quickly.