BERLIN (Reuters) - German lawmakers of Turkish origin who have been threatened after parliament declared the 1915 massacre of Armenians a genocide have been warned not to travel to Turkey and will get increased police protection, media reported on Saturday.

The resolution in Germany's parliament this month labeling the 1915 killings by Ottoman forces as genocide has added to tensions between Berlin and Ankara.

Turkish President Tayyip Erdogan has said that the 11 lawmakers of Turkish origin who voted for the resolution should be given blood tests, and has accused them of having "tainted blood" and of being terrorists.

The leader of Germany's Green party, Cem Oezdemir, who pushed for the resolution, has also received death threats.

Der Spiegel said the Foreign Ministry had warned the lawmakers against travel to Turkey because their safety could not be guaranteed. The Foreign Ministry did not immediately respond to a request for comment.

"It's unspeakable to know that it's not possible to fly there for now," Aydan Oezoguz, Germany's integration commissioner, was quoted by the magazine as saying.

Other lawmakers with Turkish roots have also canceled business trips to the country, Der Spiegel said.

Separately, the Frankfurt Allgemeine Sonntagszeitung reported that the 11 lawmakers will now receive increased police protection and further security measures for both their professional and private activities.

"The threats against lawmakers of Turkish origin are unacceptable," Interior Minister Thomas de Maiziere told the paper. "Of course security measures will be adjusted if necessary."

He stressed, however, that the majority of the 3.5 million people with Turkish roots who live in Germany were "good neighbors" and said the perpetrators were "isolated cases."

Oezdemir told the FAS that he had received threats, reading: "At some point, your German friends will have forgotten that - we won't" and "We will find you everywhere."

He also called on Turkish groups in Germany to condemn the death threats. On Thursday, the president of the Bundestag said threats against individual lawmaker were attacks on the entire parliament.

(Reporting by Caroline Copley; Editing by Kevin Liffey and Dominic Evans)