ISTANBUL (AP) — Greece’s ambassador to Turkey was summoned to the Foreign Ministry over concerns about the activities of the outlawed Kurdish Workers’ Party in his country, according to the state-run Anadolu news agency.

Turkish officials complained to Ambassador Christodoulos Lazaris about the Kurdistan Workers’ Party, or PKK, carrying out propaganda, financing and recruitment in Greece, Anadolu reported late Friday, citing diplomatic sources.

They also raised concerns about a recent demonstration near the Turkish Embassy in Athens by alleged PKK supporters and the safety of Turkish nationals in Greece.

The PKK has waged a 38-year insurgency against Turkey that has left tens of thousands dead. It is designated a terrorist organization by the U.S and the European Union.

The activities of groups in Sweden and Finland that Turkey considers to be terrorists is one of the main objections by Turkey to the Nordic states joining NATO. Ankara’s concerns threaten to hold up their bid to join the alliance following Russia’s invasion of Ukraine.

Turkey and Greece are divided over a number of issues such as maritime borders in the Mediterranean and Aegean Seas.

On Wednesday, Turkish President Recep Tayyip Erdogan said Ankara had broken off from high-level talks with Athens. The mechanism for resolving disputes between the traditional rivals was resumed last year after a five-year break.