Berlin residents were overwhelmed with messages of support and resilience after a truck was intentionally driven into a crowded Christmas market Monday evening, killing 12 people and injuring 48. Police are treating the attack as an act of terrorism just days before the Christmas holiday.
READ MORE: Berlin police say man in custody over deadly Christmas market truck attack may not be driver
“Ich bin ein Berliner,” which translates to “I am a Berliner,” began trending on social media in response to the attack, as Germans and people around the world showed support for the German capital. The phrase was made famous in 1963 after U.S. President John F. Kennedy used it to express America’s solidarity with West Berlin, which, at the time, was separated from East Berlin by the Berlin Wall.
The truck smashed into wooden huts serving mulled wine and sausages at the foot of the Kaiser Wilhelm memorial church, one of West Berlin’s most famous landmarks, at about 8 p.m. on Monday. Six of those killed are German nationals; however, authorities have yet to confirm the nationalities of the other six killed in the attack.
A Pakistani asylum-seeker was arrested in connection with the attack, but authorities now believe the real perpetrator could still be on the run. German authorities are urging those in Berlin to be vigilant.
WATCH: Berlin police say man in custody over deadly Christmas market truck attack may not be driver
“There is much we still do not know with sufficient certainty but we must, as things stand now, assume it was a terrorist attack,” said Chancellor Angela Merkel Tuesday.
“I know it would be especially hard for us all to bear if it were confirmed that the person who committed this act was someone who sought protection and asylum.”
The attack on the Christmas market comes at the end of a deadly year in Germany. In July, 10 people were killed during a shooting rampage in Munich. The gunman, 18-year-old Ali David Sonboly, was depressed, undergoing psychiatric treatment and held a hatred for foreigners. Police have also found evidence of what looks like an obsession with mass shootings.
In the aftermath of the Munich shooting, many took to social media to share heartbreaking cartoons showing support for German people. On Tuesday, those sentiments were echoed as the people of Berlin continue to come to terms with the latest attack, which put a dark twist on Germany’s historic Christmas tradition.
— With files from The Associated Press