Site of Berlin attack
Site of Berlin attackReuters

The terrorist who perpetrated the Berlin truck terror attack Tuesday night is apparently still at large in Germany, armed and dangerous to the public. Police significantly increased security measures in the country.

In the attack 12 people were killed and 50 wounded, one of them an Israeli who is in serious but stable condition. His wife is reported missing.

In the morning police arrested a 23-year-old Pakistani resident who was thought to be the terrorist. On investigation he denied any connection to the attack and police later announced that he is not the right man they were searching for.

German newspaper Die Welt quoted a Berlin police official as saying. "We have the wrong man, And therefore a new situation — that the real attacker is still at large and can do more harm.” He promised to increase security measures in Berlin's streets.

Germany's top prosecutor, Peter Frank, said the massacre could have been carried out by more than one person, adding that the suspect in custody "may not have been the perpetrator or may belong to the group of perpetrators"

Berlin police chief Klaus Kandt said investigators were "uncertain" of whether they had detained the correct suspect, while the city's police sent out a tweet warning Germans they should stay "alert".

German Chancellor Angela Merkel said it must be assumed that the attack was a terrorist attack and described herself as as "shocked, shaken and deeply saddened." She added that if it were confirmed that an asylum seeker had perpetrated the attack "this would be particularly sickening for the many, many Germans who work to help refugees every day and for the many people who really need our help and are making an effort to integrate in our country."

Merkel has come under criticism for her liberal immigrant policy and the latest attack may cause the German government to review and modify its policy towards immigrants and asylum seekers.