The director of Berlin's Deutsche Oper on Tuesday defended her decision to cancel performances of a Mozart opera over fears of how Muslims may react to one of its scenes, while the city's top security official suggested the move was a mistake.

Opera director Kirsten Harms decided to drop four performances of "Idomeneo" after a vague warning from authorities -- relayed to her by Berlin's state interior minister, Ehrhart Koerting -- that a scene featuring the severed heads of Jesus, Muhammad and Buddha could cause trouble.

Harms indicated that, with the right security guarantees, the opera could be restaged, although she offered no specific promise. The cancellation drew widespread criticism that it was a failure to defend freedom of speech.

Harms said she had been put in a difficult position after caricatures of Muhammad in a Danish newspaper ignited outrage in the Muslim world earlier this year.

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"What would have happened if something had happened and we had ignored these indications?" she asked during a podium discussion at the opera house. "That also justifiably would have been cause for great indignation."

Koerting was interrupted by heckling -- and some shouts for his resignation -- from the audience at a roughly half-full opera house. He suggested that the decision to cancel was, with hindsight, a mistake.

"It was probably wrong that the piece was not staged," he said. "In this case, I reacted in that I took a bit too much consideration of security. That may be a mistake -- but I say better a bit too much than a bit too little."

Later in the discussion, he argued that the opera should be brought back -- "we should say from our understanding of ourselves that Idomeneo should be staged again at the Deutsche Oper."

The security situation is "no worse" than before the debate erupted, he said.

Hans Neuenfels' production premiered in 2003 at the Deutsche Oper and was last staged there in 2004. Since then, it has not been performed.

Berlin's longtime cultural rival, Vienna, has shown an interest in staging the production, which adds a scene -- meant as a statement against organized religion -- in which King Idomeneo presents the severed heads not only of the Greek god of the sea, Poseidon, but also of Muhammad, Jesus and Buddha.

Germany's top Protestant cleric, Lutheran Bishop Wolfgang Huber, added his voice to those calling for the opera to be restaged as soon as possible -- but also criticized the addition of the severed heads, arguing that it showed a lack of "thoughtfulness."

Others invited to participate in the panel discussion included other city officials, an expert on Islam, and the head of another theater. Anyone who wanted to listen could get a free ticket.

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The response to Harms' decision from Germany's Islamic community has been mixed, with some praising it and others urging Muslims to accept the role of provocation in art.

At the Mariendorfer Moschee, a mosque in Berlin's Tempelhof district, two worshippers shrugged off the controversy.

"I think it's wrong to drop it," said Gulsah Yilmaz, a 19-year-old history student, whose parents come from Turkey. "If they've been playing it for years, that means it was successful or there was demand for it -- that's their thing. I did not call for this."

Hasan Akyol, a 44-year-old retail salesman and Turkish native, said that "art is art" -- although religious feelings should be respected.

The decision to drop the opera "is incomprehensible to me," he added. "Why do they do this? Do they want to create trouble?"