Turkey's Foreign Ministry summoned Sweden's embassy's chief of mission in the country to express the government's "strong reaction" to a Kurdish group's protest in Gothenburg this week.

Officials told Sweden's interim chief of mission in Ankara that the gathering is "terrorist propaganda", according to Reuters and multiple Turkish media outlets citing unidentified diplomatic sources.

The latest escalation in Stockholm's relationship with Turkey comes after Erdogan threatened to veto Sweden and Finland's NATO membership due to concerns that the Nordic countries are harboring Kurdish militants. 

Last month in Madrid, the countries signed a tripartite memorandum in which Sweden and Finland pledged to lift their arms embargo against Turkey and crack down on individuals and groups designated as terrorists by Ankara.

Commenting on the Gothenburg protest, Turkish diplomatic officials said: “In this context, our expectations for identifying the perpetrators of the action, taking the necessary legal and judicial measures, and taking concrete steps in light of the commitments recorded in the tripartite memorandum were emphasized.”

It is worth noting that the protest on Wednesday included supporters of the PKK and other Kurdish organizations that Turkey has designated as terrorist organizations. 

Social media images and videos show demonstrators holding pro-Kurdish banners, including PKK flags. 

According to Turkish media reports, the group's flags were also hoisted on several poles in the city center, and some marchers carried a banner that read, "We are all PKK."

Erdogan warned this week that Turkey may still "freeze" Sweden and Finland's NATO applications if they do not meet the terms of the Madrid Agreement. "Sweden, in particular, has a bad reputation on this issue," he stressed.

Read more: Turkey's demands to NATO revealed