In a tweet, Alice Weidel, the parliamentary group leader of the Alternative for Germany, the country's largest opposition party, implied a connection between the blaze which broke out on Monday evening and previous anti-Christian “attacks” in France.

“During Holy Week #NotreDame burns. March: second largest church Saint-Sulpice burns. February: 47 attacks in France,” Weidel wrote.

“The Observatory on Intolerance and Discrimination Against Christians in Europe speaks of a significant increase,” she added, including a link to a March article in a German Catholic magazine headlined “Catholic churches desecrated across France”.

The Notre-Dame blaze, which brought the iconic building's towering spire and roof crashing down, is being treated by French investigators as an “involuntary fire” and they have advanced no other theory.

The cathedral had been undergoing intensive restoration work which firefighters said could be linked to the inferno.

The brief fire on March 17th at Saint-Sulpice, a Roman Catholic church in Paris, left no one hurt and little damage. Investigators have opened an inquiry into the blaze.

The Observatory on Intolerance and Discrimination Against Christians in Europe cited by Weidel is a non-governmental organisation based in Austria.

It told AFP by email that while a partner organization had found an increase in attacks on French churches this year, it had no indication that Notre-Dame had been targeted.

We “will wait with the rest of the public for an official announcement after an investigation into the cause of the fire,” it added.

The AfD, which holds more than 90 seats in the Bundestag lower house of parliament, rails against Islam and Muslim immigrants as a threat to Christian culture in Germany and Europe.

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