“Recent developments with threats targeted at Sweden and Swedish interests are serious and affect Sweden’s security,” the Swedish security service Sapo said in a statement.

“The developments mean that Sweden is deemed to be in greater focus than previously for violent Islamic extremists globally.”

Sweden and neighbour Finland last year launched bids to join Nato, following Russia’s invasion of Ukraine.

The membership process has been held up by Turkey, which says the two Nordic countries, primarily Sweden, are not doing enough to fight terrorism.

The burning of the Quran by a far-right politician outside the Turkish embassy last month has ratcheted up tensions.

Thousands of Afghans took to the streets to protest after Rasmus Palundan’s actions, which also provoked anger in other parts of the Muslim world.

Turkey has also strongly condemned a stunt in which an effigy of President Recep Tayyip Erdogan was hanged in Stockholm by protesters.

Sweden has warned its citizens in Turkey to avoid crowds and demonstrations.

Sapo said it had not raised its formal assessment of the threat level against the country, which is at three on a scale up to five, equivalent to “elevated”.

“The terror threat level is based on a long-term assessment which means that if the developments continue for a time, the threat level could be raised,” Sapo said.