A Greek coast guard vessel and a Turkish patrol boat collided on Wednesday in the eastern Aegean Sea in what appears to have been an attempt to challenge Greece’s territorial waters, Kathimerini understands.

The Greek Foreign Ministry said in a statement that a complaint would be made to Ankara over the incident, which took place near the Dodecanese island of Farmakonisi.

There were no reports of injuries.

Tension reportedly broke out early on Wednesday when a Turkish patrol boat, which had breached Greek territorial waters, approached a Slovenian patrol boat operating for the European Union’s border agency Frontex and demanded that it withdraw from what the Turkish crew claimed were Turkish territorial waters.

The captain of the Slovenian vessel, which was taking part in Frontex’s joint Operation Poseidon against illegal immigration, allegedly responded by contacting the Greek authorities. A Greek coast guard vessel was immediately sent to the spot.

According to coast guard officers, the Turkish captain asked the Greek vessel to withdraw. The Greek captain turned down the request and reportedly told his Turkish counterpart: “This is Greece. You will have to leave right away.”

According to reports, the Turkish boat then tried to ram the Greek vessel, but failed. Maneuvers by the Greek captain led the two vessels to collide head-on.

Both sides are said to have armed their weapons during the standoff.

“The Turkish coast guard vessel was sailing dangerously and collided with a Greek coast guard vessel,” a statement by the Foreign Ministry said.

“Instructions have been given to the Greek Embassy in Ankara for a demarche,” the ministry said. Such incidents, it said, damage bilateral ties and undermine efforts to tackle illegal immigration.

Over the past few years, increasing numbers of asylum seekers and illegal immigrants have used the Aegean Sea as a gateway to the EU.

Merchant Marine and Aegean Minister Costas Mousouroulis is expected to meet the Turkish ambassador to Greece, Kerim Uras, on Thursday.