A lorry ploughed into a busy Christmas market in Berlin on Monday, killing at least nine people and wounding 50 more in what police said was a possible terror attack.
Ambulances and police rushed to the area after the driver drove up the pavement of the market in a central square popular with tourists, in scenes reminiscent of the deadly truck attack in the French city of Nice in July.
"There are at least 50 injured... some seriously. Some are dead," a police spokeswoman told AFP.
Police subsequently said nine had been killed and that one person has been detained over 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.
Germany has been shaken this year 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 Syrian asylum-seekers.
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.
The 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 Islamist militant 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.
The massacre on the palm-fringed Promenade des Anglais was the latest in a series of militant attacks that have rocked France over the past two years.
The violence began with the January 2015 attacks on a satirical newspaper and a Jewish supermarket in Paris and continued 10 months later with coordinated strikes on the capital's Bataclan concert hall, national stadium and cafe terraces.
The attacks have hardened attitudes on security and immigration, fuelling the rise of the far-right ahead of next year's presidential election
Another 11 people were arrested lat week in France suspected of helping to arm Bouhlel.