German novelist Guenter Grass has admitted in an interview that he served in the Waffen SS, the combat arm of Adolf Hitler's dreaded paramilitary forces, during World War II, a German newspaper reported. In the interview, published Saturday by the daily Frankfurter Allgemeine Zeitung, the Nobel Prize winner discusses a memoir about his youth and the war years, slated for publication next month. Asked why he was making the disclosure now, Grass was quoted as saying, "It weighed on me. My silence over all these years is one of the reasons I wrote this book. It had to come out, finally." Grass said that after the war he was ashamed of having been in the Waffen SS. "At the time, no," he said. "Later this feeling of shame burdened me." Grass, 78, is regarded as the literary spokesman for the generation of Germans that grew up in the Nazi era and survived the war. He won the Nobel Prize for Literature in 1999 for works including his 1959 novel, The Tin Drum, made into a Oscar-winning film in 1979. He was long been active in leftwing politics as a sometimes-critical supporter of the Social Democratic Party, and is regarded by many as an important moral voice against xenophobia and war. He was quoted as saying he had orginally volunteered for the submarine service at age 15, but was not accepted, only to be called up at 17 to the Waffen SS 10th Armored Division "Frundsberg," in Dresden. Grass said he volunteered for military service to get out of the confinement he felt as a teenager in his parent's house. He had been in the Arbeitsdienst, a force of laborers helping the military. "It happened as it did to many of my age," he said. "We were in the labor service, and all at once, a year later, the call-up notice lay on the table. And only when I got to Dresden did I learn it was the Waffen SS." The SS, Schutzstaffel or "Protective Echelon" in German, started as a small personal bodyguard for Hitler headed by top Nazi Heinrich Himmler. It later became a huge organization that ran concentration camps and carried out mass executions of political opponents, Jews, Gypsies, Polish leaders, Communists, anti-Nazi guerrillas, and Soviet POWs. It included the Waffen SS, a combat force that took part in fighting alongside units of the regular army and gained a reputation as fanatical fighters. The SS was declared a criminal organization by the Nuremberg war crimes tribunal after the war. Grass gave few details of his service in the interview. He said he managed to give himself jaundice to get out of training for several weeks. Grass said it was easy to forget the pull of Nazi indoctrination on teenagers. He was quoted as saying that, "for me, because I am sure of my recollection, the Waffen SS was nothing frightful, but rather an elite unit that they sent where things were hot, and which, as people said about it, had the heaviest losses." "One forgets easily, in what a skillful and modern way the Hitler Youth and Jungvolk were raised, as a preliminary level," he said, referring to the Nazi youth organization and its subdivision for younger boys. "Hitler's slogan that "youth must be led by youth' was tremendously effective." Previous biographical material on Grass, such as a timeline on the Web site of the German Historical Museum, says he served as a helper on anti-aircraft crews, a common duty assigned to teenagers during the war. He was known to have been wounded and taken prisoner by US forces after the war. Grass's admission divided commentators. Grass had no way of defending himself from "what the propaganda and agitation apparatus of the Nazis had achieved then," Ralph Giordano, a German Jewish essayist, told WDR2 radio. He welcomed Grass's decision to go public. However, Michael Wolffsohn, a prominent military historian, faulted him for waiting so long. Grass's "moralizing, though not his storytelling, life's work is devalued by his persistent silence," Wolffsohn wrote in the online Netzeitung daily. Nazi hunter Efraim Zuroff who heads the Israel office of the Los Angeles-based Simon Wiesenthal Center said Saturday in a first response that it was not immediately clear whether the SS unit Grass served in took part in war crimes. "The fact that he served in the Waffen SS does not automatically make him a Nazi war criminal," Zuroff said. He added that the center will examine the newly revealed information about the German novelist's past.