World leaders are expressing their condolences and calling for a unified response to what happened in Berlin.
The French parliament held a moment of silence, lawmakers there especially sympathetic - since facing their own truck-driven terror attack in Nice in July. President Francois Hollande extended "solidarity" and "compassion" to his immediate neighbor.
"France knows what a terrorist attack brings, what it can provoke -- despair and at the same time, hardship; and how we must be united. It is true for a country when it's been struck, it's true for the whole of Europe and even for the whole world, in the face of terrorist threat," Hollande said.
China's President Xi Jinping expressed his "heartfelt sympathy" in a statement, saying China was ready to "strengthen anti-terrorism cooperation with the international community, including Germany."
U.S. President Barack Obama, who's been taking a break in Hawaii, called his German counterpart on the phone to offer assistance and appreciation for Chancellor Angela Merkel's leadership in what he called "our shared efforts to root out the scourge of terrorism and defend our way of life."
His successor Donald Trump released a statement, blaming "Islamist terrorists" for the attack - and pledging to "eradicate" terror networks from the face of the earth.
In Italy, France and the UK, authorities said they were stepping up public security efforts while stressing international coordination.
"Well I think it's very important to stress that our security services and our intelligence agencies do an absolutely extraordinary job of keeping us safe. As you have heard me say many times over the years, in this city alone we monitor thousands of people the whole time, but you can never be complacent. The risk is very real and that is why it is so important of us to collaborate as we do with our German friends, with our Turkish friends and of course with the Russians as well," British Foreign Secretary Boris Johnson said.
Though dealing with the death of his Turkish ambassador, Russian President Vladimir Putin called the Berlin attack a "shockingly cruel and cynical crime."
