Security and rescue workers tend to the area after a lorry truck ploughed through a Christmas market on December 19, 2016 in Berlin, Germany.

U.S. President-elect Donald Trump on Monday condemned an attack at a Christmas market in Berlin that killed nine people and injured dozens more, linking the attack to "Islamist terrorists" before German police officials had said who was responsible.

Trump, in a statement, said "ISIS and other Islamist terrorists continually slaughter Christians in their communities and places of worship as part of their global jihad," using an acronym for Islamic State.

On Twitter, he said the attack, along with others in Turkey and Switzerland, showed "it is only getting worse. The civilized world must change thinking!"

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