Alternative for Germany's (AfD) North-Rhine Westphalia State Chairman Marcus Pretzell, who is also AfD Federal Chairwoman Frauke Petry's partner, started it off with a tweet: "These are Merkel's dead," he wrote shortly after news of the attack broke. Petry herself then wrote, "Germany is no longer safe," calling for increased police and intelligence service powers, as well as the rigorous deportation of potential terrorists and so-called threatening persons. "Close the borders immediately," and "re-migrate instead of importing terror" was the message put out by the rightwing populist "Identitarian Movement." Meanwhile, the list of similar tweets has grown considerably longer. Many people agree with such sentiments and have retweeted these and similar statements.

Warnings against a blanket suspicion of refugees

Others are standing up against such ideas. German Parliamentary President Norbert Lammert, for instance, warned against rushing to place blame. "Those who offer such public explanations immediately after attacks are not interested in finding a solution to the problem, rather they simply seek to use the attacks to serve their own ends," said Lammert. Green Party Chairman Cem Ozdemir accused the AfD of using the Berlin attack to incite xenophobic resentment.

The chairman of the German Bishops' Conference, Reinhard Marx, also warned against the general suspicion of refugees. "It would be disastrous if we were to say: Aha! Now it is clear - the refugees are the problem. We cannot afford to give these terrorists an added success by attacking each other, by not sticking together, and by approaching the problem ruthlessly and with hate in our hearts," said Marx.

'Looking to gain influence'

Gudrun Hentges, a right-wing extremism researcher and political science professor at the University of Cologne, is not surprised by the demands being made by right-wing populists. She told DW that the reactions clearly illustrate that populists have been waiting for a terror attack to take place in a major German city in order to instrumentalize it. "Refugees will be put under blanket suspicion and populists will attempt to interpret the current situation as one of absolute threat."

Hentges fears they will also try to gain influence when it comes to domestic security and deportation policy. "It remains to be seen how this will evolve within Germany's ruling coalition, but in many instances, the rightwing populists make demands that the government later picks up on. So I see the attack as a major threat to the refugee debate."

'State of war'

Harsh words have already been coming from the Union (Christian Democratic Union/CDU and Christian Social Union/CSU). After the Berlin attack, Saarland Interior Minister and Chairman of the German Interior Ministers' Conference, Klaus Bouillon, said: "We are in a state of war, although those who always want to see the good in people don't want to admit it." He announced that, when necessary, "heavily armed" police would be deployed in the future. "That means: long rifles, small arms and machine guns." And CSU leader Horst Seehofer wants to conduct a complete review of refugee policy. "We owe it to the victims, those affected and the entire populous to rethink and adjust our entire immigration and security policy," said the Bavarian prime minister.

Political scientist Hentges fears that such statements signal that the attack will affect Germany's upcoming parliamentary elections. She adds that calls for more security are limited by reality, and that refugees cannot simply be put under around-the-clock surveillance.

'There is no such thing as 100 percent security'

Hentges says that since the threat of radicalization increases when refugees remain isolated, increased prevention and integration measures would provide more adequate security against further attacks than control alone. But one thing remains clear: "There is no such thing as 100 percent safety; nowhere in the world." Politicians must tell that to the people honestly instead of creating hysteria, says the professor.

Oliver Malchow, chairman of Germany's Police Trade Union, expressed a similar attitude towards calls for increased security measures. He told the radio station Bayerischen Rundfunk (Bavarian Broadcasting) that with 2,500 Christmas markets in Germany, there was no way to provide "100 percent safety."

In general, state and federal interior ministers agree that Christmas markets across the country should continue to operate. During a conference call they decided that appropriate measures designed to increase security should be planned and implemented "on site." Berlin Interior Minister Andreas Geisel announced, however, that Christmas market operators in the capital had been asked to remain closed for one day, out of respect for victims and their families.