BERLIN - German politicians rebuked the co-leader of the anti-immigrant Alternative for Germany (AfD) party after he made comments to his party that appeared to play down the significance of the Nazis in Germany's history."Hitler and the National Socialists are just bird shit in 1,000 years of successful German history," AfD lawmaker Alexander Gauland told a party gathering in the eastern state of Thuringia, according to a tweet by his party spokesman. The comments were also carried by German newspapers, such as Der Spiegel, with reports from the event.Lars Klingbeil, general secretary of the Social Democrats (SPD), criticized Gauland for trivializing the Nazis. "It is a disgrace that such characters sit in parliament," he said.Gauland was elected AfD co-leader in December, three months after the party became the third-biggest party in the Bundestag lower house of parliament.The Nazi dictatorship remains a highly sensitive issue in Germany, more than seven decades after its defeat.Germany has built its post-World War Two identity on the principle of keeping alive the memory of the six million Jews murdered by the Nazis and a commitment to Israel's right to exist."Our German history has shown that Nazism, hate and incitement lead to the abyss," said Katrin Goering-Eckardt of the Green party, describing Gauland's comments as "an incredible blow above all in the face of Holocaust survivors, their descendants and relatives."Hours after the speech, AfD spokesman Christian Lueth sent another tweet, this time with a black and white picture of an angry-looking Hitler with his fist in the air and the caption: "By the way I find the idea of comparing #Hitler to bird shit quite charming."The AfD has drawn its support from voters angry at Chancellor Angela Merkel's decision in 2015 to welcome about a million people seeking asylum.Annegret Kramp-Karrenbauer, general secretary of Merkel's Christian Democrats and a close ally of Merkel tweeted: "50 million war dead, Holocaust and total war are only 'bird shit' for the AfD and Gauland!"