A German MP of Turkish origin, Cem Ozdemir, says he has received death threats over Germany's recognition of the 1915 massacre of Armenians by Ottoman Turks as genocide.
Turkish President Recep Tayyip Erdogan castigated German MPs for the vote. He scorned the 11 MPs of Turkish origin, saying, "What sort of Turks are they?"
"Their blood must be tested in a lab," he said.
Ankara's mayor showed the 11 in a tweet saying they "stabbed us in the back".
Turkey recalled its ambassador from Berlin in fury after the German parliament on Thursday voted overwhelmingly for the Armenian "genocide" resolution.
Armenians say up to 1.5 million of their people died in the atrocities of 1915, during the Ottoman Empire's collapse in World War One. Turkey says the toll was much lower and rejects the term "genocide".
Mr Ozdemir, co-leader of the German Greens, was one of the initiators of the resolution. Police have now beefed up his personal security.
Commenting on the death threats he had received, he said: "Unfortunately there is a Turkish Pegida too" - referring to the German nationalist movement that has staged anti-immigration and "anti-Islamisation" rallies.
His assistant Marc Berthold said "we're well used to abuse and insults, but we've never experienced so many death threats before".
A fellow German Green MP of Turkish origin, Ozcan Mutlu, deplored the tweet from Ankara Mayor Ibrahim Melih Gokcek. According to German media, it was retweeted by many Turkish nationalists, some of whom made death threats.
Mr Mutlu told German ARD television he was worried that "some utterly crazy people might take note of this and think the command has come from on-high".
Turkish nationalists who rallied against the German MPs' vote made the sign of the Grey Wolves, a nationalist group that has murdered leftists and liberals in the past.
At the weekend Mr Erdogan also accused the Turkish-origin German MPs of acting on behalf of the Kurdistan Workers' Party (PKK), which is banned in Turkey and fighting government forces in the Kurdish-majority south-east of the country.
"They are the German extension of the separatist terrorist organisation," he alleged.
Lashing out at the German parliament in general, Mr Erdogan said Germany "should be the last country to vote on a so-called 'genocide' by Turkey".
"First, you have to account for the Holocaust and how you massacred more than 100,000 Namibians," he said, referring to Nazi Germany's extermination of Jews and the earlier German slaughter of Hereros in former South-West Africa.
Separately, German Justice Minister Heiko Maas said he had also received many death threats from German far-right extremists.
Armenian genocide dispute
- Hundreds of thousands of Christian Armenians died in 1915 at the hands of the Ottoman Turks, whose empire was disintegrating
- Many of the victims were civilians deported to barren desert regions where they died of starvation and thirst. Thousands also died in massacres
- Armenia says up to 1.5 million people were killed. Turkey says the number of deaths was much smaller
- Most non-Turkish scholars of the events regard them as genocide - as do more than 20 states including France, Germany and Russia, and some international bodies such as the European Parliament
- Turkey rejects the term "genocide", maintaining that many of the dead were killed in clashes during World War One, and that many ethnic Turks also suffered in the conflict