A German police investigator rests at a Christmas market following an accident with a truck that ploughed into a crowd on Breitscheidplatz square near the fashionable Kurfuerstendamm avenue in the west of Berlin, Germany, December 19, 2016. [Photo/Agencies]

WEST PALM BEACH, Fla.- US 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!"