Authorities cast a Europe-wide net in a frantic search for a suspect in Monday's deadly attack on a Christmas market in Berlin, an act of violence that will test Germany's commitment to tolerance and openness.
The suspect, Anis Amri, is a 24-year-old migrant from Tunisia who was under surveillance for six months this year for potential terrorist activity. Germany rejected his application for asylum in July and attempted to deport him.
German authorities warned Mr. Amri, who has used at least six aliases, could be violent and armed. They offered a €100,000 ($140,000) reward for information leading to his capture.
The attack in Berlin, which killed 12 people and injured 48, is the culmination of months of fears. Until now, Germany had avoided a major attack inspired by the militant group the Islamic State, which claimed responsibility for Monday's violence.
Now Germany, too, faces a struggle over what lessons the public will draw from the attack. German leaders have voiced their support for unity and calm in the wake of the killings, striving to prevent the situation from casting suspicion on asylum seekers and Muslims.
"These acts do not undermine our convictions," German President Joachim Gauck said in remarks on Tuesday.
"The hatred of the perpetrators will not mislead us into feeling hatred ourselves."
Meanwhile, an upstart right-wing, anti-immigration party called Alternative for Germany has seized upon the attack as vindication of its warnings about the dangers of a large influx of migrants and refugees from the Middle East and North Africa in 2015.
But such rhetoric, however, has been met with condemnation by a number of German politicians and commentators, who say it vilifies asylum seekers, the vast majority of whom are in no way violent. An umbrella group of Muslim organizations in Germany condemned the attack in the strongest possible terms.
On Wednesday, in a remarkable show of solidarity, a choir from the church at the site of the attack and a group of refugees gathered at the square where people were killed and sang songs together, according to videos posted online. They held signs reading "You will not divide us" and "Berlin sticks together."
Later in the evening, a small group of right-wing extremists staged a protest near the site of the attack, but they were met by a much larger group of counterdemonstrators.
The duelling impulses were also on display in the front pages of Berlin's newspapers on Wednesday morning. Bild, the country's bestselling tabloid, printed "Fear!" in large letters below a photo of the truck used in the attack.
By contrast, the Berliner Morgenpost, a local newspaper, used an image of the Brandenburg Gate lit up in the colours of the German flag. "Do not be afraid!" its headline read. "We mourn the victims of the attack on Berlin."
Mark Swatek, a lawyer in Berlin who specializes in asylum cases, said he bought a copy of the Berliner Morgenpost on Wednesday – which he never does – in recognition of its measured response to the tragedy.
He predicted that the right-wing Alternative for Germany will gain more support in the country's elections in the wake of the attack. But he doesn't believe it can mount a credible challenge to the mainstream parties that dominate the country's parliament. "I am relatively confident in the liberal backbone of Germany to get us through this," Mr. Swatek said.
Across Berlin, Christmas markets reopened for their final days of shopping and socializing before the holiday, albeit with a heavy police presence. Berlin Mayor Michael Mueller said it was "good to see that Berliners aren't being intimidated."
Some details are beginning to emerge about the victims of Monday's attack. According to media reports, those killed include an Italian, an Israeli and at least three Germans. Lukasz Urban, the 37-year-old Polish driver of the truck, was also killed, possibly after a struggle with the perpetrator.
A wallet holding an identity document for Mr. Amri, the suspect, was found in the truck. He arrived in Germany in July, 2015, according to authorities. In March of this year, law-enforcement authorities launched an investigation of him after receiving a tip that he was planning a theft and would use the proceeds to buy automatic weapons for an attack. The surveillance of Mr. Amri was halted in September.
Separately, Mr. Amri's asylum application was rejected in July. German authorities prepared to deport him but weren't able to do so because he didn't have valid identity papers. In August, they started trying to get him a replacement passport.
Ralf Jaeger, the Interior Minister of western North Rhine-Westphalia state, said Wednesday that Tunisia at first denied that Mr. Amri was a citizen. "The papers weren't issued for a long time," he said. "They arrived today."
With a report from Associated Press