The head of government, during her visit to the attack site on Tuesday, was accompanied by Interior Minister Thomas de Maizière, Foreign Minister Franz-Walter Steinmeier and the governing mayor Michael Müller, Efe news reported.
The German dignitaries laid flowers at the site where citizens had left messages of condolence. An assailant on Monday drove a truck into a crowd of people who had gathered at the Christmas market in Breitscheidplatz, Berlin.
In a conference held earlier at the German Chancellery, Merkel expressed her shock, sadness and indignation at the attack, adding that she thought it would be particularly repugnant if the perpetrator was someone who came to country seeking refuge.
She said the nation should refuse to live in fear because of the events. Following the attack, a Pakistani asylum-seeker was arrested on suspicion of carrying out the alleged terror attack.
However, head of Berlin police Klaus Kandt has since said they have doubts that the detainee, who denied any involvement in the incident, was in fact the assailant.
Further, federal prosecutor Peter Frank said they were not ruling out the possibility that the attack was committed by a group of people.