A man tore up and burned a Koran outside Stockholm’s central mosque on Wednesday, an event that risks angering Turkey as Sweden bids to join NATO, after Swedish police granted permission for the protest to take place.

Police later charged the man with agitation against an ethnic or national group.

A series of demonstrations in Sweden against Islam and for Kurdish rights have offended Ankara, whose backing Sweden needs to gain entry to the North Atlantic Treaty Organisation.

Sweden sought NATO membership in the wake of Russia’s invasion of Ukraine last year. But alliance member Turkey has held up the process, accusing Sweden of harbouring people it considers terrorists and demanding their extradition.

Turkish Foreign Minister Hakan Fidan condemned the act in a tweet, adding that it was unacceptable to allow anti-Islam protests in the name of freedom of expression.

Burning of religious texts is “disrespectful and hurtful”, the deputy spokesperson for the US State Department told reporters in a daily briefing. “What might be legal is certainly not necessarily appropriate,” Vedant Patel said.

But he continued to urge Turkey and Hungary to ratify the NATO accession protocol of Sweden without delay. “We believe Sweden has fulfilled its commitments under the trilateral memorandum.”

Some 200 onlookers witnessed one of the two protesters tearing up pages of a copy of the Koran and wiping his shoes with it before putting bacon in it and setting the book on fire, while the other spoke into a megaphone.

Some of those present shouted “God is Great” in Arabic to protest against the burning, and one man was detained by police after he attempted to throw a rock.

A supporter of the protest shouted “let it burn” as the holy book caught fire.

While Swedish police have rejected several recent applications for anti-Koran demonstrations, courts have overruled those decisions, saying they infringed on freedom of speech.

Prime Minister Ulf Kristersson told a press conference on Wednesday he would not speculate about how the protest could affect Sweden’s NATO process.

“It’s legal but not appropriate,” he said, adding that it was up to the police to make decisions on Koran burnings.

Representatives of the mosque were disappointed by the police decision to grant permission for the protest on the Muslim holiday of Eid al-Adha, mosque director and Imam Mahmoud Khalfi said on Wednesday.

“The mosque suggested to the police to at least divert the demonstration to another location, which is possible by law, but they chose not to do so,” Khalfi said in a statement.

Up to 10,000 visitors attend Stockholm’s mosque for Eid celebrations every year, according to Khalfi.

Turkey in late January suspended talks with Sweden on its NATO application after a Danish far-right politician burned a copy of the Koran near the Turkish embassy in Stockholm.