A security guard closes the gate of the German-funded Istanbul High School in Istanbul on Dec. 19. The school's Turkish management allegedly has banned Christmas celebrations at the school. (Sedat Suna/European Pressphoto Agency)

Call it the high school that stole Christmas.

As the holiday season approached, the administration of ­Istanbul High School — an academy in Muslim-majority Turkey partly funded by the German government — took a highly unusual step. It instructed, according to an email obtained by Germany’s DPA news service, that Christmas this year should be kept under wraps.

No teaching of Christmas customs.

No celebrations.

And certainly no Christmas caroling.

In fact, German officials confirmed, the school’s choir canceled its traditional Christmas concert performance at Germany’s consulate in Istanbul.

The school, at which many classes are taught in German, is prestigious in Turkey and counts at least three Turkish prime ministers as alumni. German taxpayers pay about 1 million euros annually to support it, and news of the restrictions quickly sparked an uproar in the heart of Europe, where a debate about conservative Islam is raging.

German politicians and social-media pundits were attacking the Islamic-tinged and authoritarian government of Recep Tayyip Erdogan for allegedly creating an environment in Turkey — the birthplace of Saint Nicholas — in which Christmas has become politically incorrect.

In a statement since taken down from its website, the school’s administration insisted that it had not instituted a Christmas ban. Rather, it was responding, it said, to actions by German teachers — about 35 of whom work at the school — that could seem to promote Christianity.

The school said it had taken steps after the German teachers dealt with “Christmas and Christianity in a way which the curriculum does not provide for” and that “viewed from the outside opens the door to [accusations] of manipulation,” according to German media outlets.

In an email to The Washington Post, Volker Schult, the head of the school’s German department, declined to comment.

But plenty of other Germans were commenting.

On Sunday, Germany’s Foreign Ministry called the incident ­“regrettable,” even as social-media pundits and politicians across the political spectrum fumed.

“The German government mustn’t accept the Christmas ban by the Turkish authorities,” Markus Söder, a member of the conservative Christian Social Union (CSU), told the daily Bild. He later added, “Erdogan is consciously breaking the bridges to Europe.”

Andreas Scheuer, the CSU’s secretary general, said in an interview with Funke media group that the school actions were infringing upon religious freedom.

Speaking to Berlin daily Der ­Tagesspiegel on Sunday, Left Party lawmaker Sevim Dagdelen called on Berlin to summon the Turkish ambassador and to send an official protest to Ankara.

“It shows how far the AKP’s ­Islamist madness is going, if even Christmas is declared a taboo at a school, which is sponsored with German tax money,” Dagdelen said, referring to Turkey’s ruling Justice and Development Party.

As the incident appeared to be spiraling into a four-alarm fire in the 24-hour news cycle, however, the German Foreign Ministry sought to calm things down. On Monday, ministry spokesman Martin Schäfer emphasized the importance of long-standing ­German-Turkish cultural relations and said Germany stood firmly by Turkey's side in the face of recent terrorist attacks.

He expressed surprise that the issue had created such a huge media echo.

“We let the media know yesterday that we found it hard to understand and were surprised that apparently the school administration gave the instruction not to talk about Christmas, sing Christmas songs and not to discuss the subject matter,” he said. “But this is not a Christmas ban. . . . Nobody in Turkey is banning anyone from celebrating Christmas.”

He added that there have been fresh talks between the school administration and Turkish and German officials and that “the problem” is “likely to be resolved shortly.”

“I’m very confident that the school will soon inform you that hopefully all misunderstandings will have been resolved and that, of course, teachers at this school, which is rich in tradition, will be able to talk about German Christmas customs,” Schäfer said.

Turkish politicians, meanwhile, pushed back on social media, arguing that the issue was being blown out of proportion.

Tweeting an image of brightly lit Christmas trees in Istanbul, AKP politician Mustafa Yeneroglu, wrote: “Some examples of christmas ban pictures in #Turkey. Should I ask for ramadan images in GER?”