5TH LEAD Germany seeks Tunisian suspected extremist over deadly truck attack By Friederike Heine, dpa

Berlin (dpa) - German police are hunting a Tunisian suspect over the Berlin truck attack who had been known to authorities as a potential terrorist and whose request for asylum had been denied, a security source told dpa Wednesday.The suspect, named by German media as Anis A, is considered by Germany‘s domestic intelligence agency as a so-called Gefaehrder - which literally means endangerer - who is prepared to commit acts of terrorism at any time.Police say intelligence services are currently monitoring 549 of these potential terrorists.Regional newspaper Allgemeine Zeitung reported that the 21-year-old Tunisian‘s immigration papers were found inside the vehicle and that he is known to authorities under three other aliases.The Bild tabloid linked the suspect to Ahmad Abdelazziz A - an Iraqi man widely known under his nom de guerre Abu Walaa - the suspected head of a group that recruited for and provided financial and logistical support to Islamic State.The high-profile imam was arrested in western Germany alongside four other suspected extremists in November.Another security source told dpa police were about to embark on a police operation related to the attack in the western state of North Rhine-Westphalia. Bild reported that the suspect is registered in Cleves, a town near the Dutch border that is in the same state.German Interior Minister Thomas de Maiziere confirmed that there was a new suspect in the case, but said that speculation about his identity was premature.Berlin police said they had received more than 500 tips about the attack, which occurred on Monday when a large truck laden with steel ploughed through a Christmas market in a shopping district, leaving 12 dead and dozens injured.Shortly afterwards, a 23-year-old Pakistani asylum seeker was apprehended based on a description from a witness. He was later released after no evidence was found linking him to the crime.The RBB broadcaster reported Wednesday that another suspect had been detained overnight to Wednesday and later released due to insufficient evidence.Joerg Radek, head of the DLF police union, told Deutschlandfunk radio that the investigation was focusing on DNA and other traces from the crime scene, an evaluation of the truck‘s GPS data and material found on mobile phones confiscated at the scene.Islamic State claimed responsibility for the attack through its official Aamaq news agency, saying that one of its soldiers had acted in response to calls to target citizens of the coalition of states fighting the terrorist group.Islamic State often issues claims of responsibility for attacks in which it had no or only a limited role.The German anti-immigrant group Ein Prozent said it would rally outside the Berlin chancellery at 6 pm (1700 GMT) on Wednesday, adding that Alexander Gauland and Bjoern Hoecke - senior members of the right-wing Alternative for Germany (AfD) party - would attend.Berliner Buendnis gegen Rechts, a left-wing group, said it would rally at Berlin‘s Hardenbergplatz at 5 pm to commemorate "the victims and those left behind" and to protest the actions of groups "using this crime to sow seeds of hate and to divide our society."Mayor Michael Mueller told ZDF it is "good to see that Berliners aren‘t intimidated" after the attack, and that the city was "standing together for our liberal life in Berlin. "I don‘t think there‘s any need to be afraid - the police presence has been significantly heightened," he said.Fourteen of those injured in the carnage remain in a life-threatening condition. German President Joachim Gauck visited Berlin‘s Charite hospital early Wednesday to meet victims and later said that he had met a man who had been struck by a beam while aiding an injured person.In a brief statement outside the hospital, the head of state said that he "reminded (the victims) of their innate strength."German Foreign Minister Frank-Walter Steinmeier and his Italian counterpart, Angelino Alfano, visited the site of the attack to pay their respects to the victims.The Christmas market there is set to reopen on Thursday, a spokeswoman for the Schaustellerverband fairground organization said.