Two Greek coast guard boats opened harassment fire on a cargo ship in international waters in the Aegean some 18 kilometers (11 miles) off Türkiye's southwestern coast of Bozcaada on Saturday, diplomatic sources said.

The Comoros-flagged "Anatolian" ship with a crew of 18 – six Egyptians, four Somalis, five Azerbaijanis and three Turkish nationals – was attacked while sailing in international waters, the Turkish Coast Guard Command said in a statement.

After learning about the incident, the Turkish coast guard dispatched two boats and the Greek boats left the area.

No one was injured on the ship, it added.

The Turkish Coast Guard Command shared a video on its website of the harassment fire and a map pinpointing the location where the incident occurred

Diplomatic sources said that an explanation and investigation into the incident "that is totally in violation of international laws" has been demanded from Athens and protested.

Following Turkish accusations of harassment fire, the Greek coast guard confirmed it fired warning shots at a ship that was "moving suspiciously" in Greek territorial waters off the island of Lesbos.

The Anatolian was anchored Sunday in the Dardanelles Strait off the Turkish coast, Anadolu Agency (AA) reported.

The alleged incident comes at a time of heightened tensions between the two NATO ally neighbors.

Ankara recently accused Athens of "occupying" some Aegean islands and harassing Turkish jets with Russian-made S-300 defense systems stationed there. Athens denies the claims.

Türkiye has stepped up criticism of Greece stationing troops on islands in the Eastern Aegean, near the Turkish coast and in many cases visible from shore. These islands were required to be demilitarized under the 1923 Treaty of Lausanne and the 1947 Treaty of Paris, so any troops or weapons on the islands are strictly forbidden.

It was reported recently that Turkish jets on a reconnaissance mission, flying in international airspace, had been harassed by the Greek defense system stationed on Crete.

Türkiye is planning to submit to NATO and its allies the radar logs showing how a Greek S-300 air defense system harassed Turkish F-16 jets during a mission in international airspace.

On the other side, this week, the Greek government wrote letters to NATO, the European Union and the United Nations, asking them to formally condemn increasingly aggressive talk by Turkish officials and suggesting that tensions could escalate into open conflict.

Greek Foreign Minister Nikos Dendias said the behavior of Türkiye risked "a situation similar to that currently unfolding in some other part of our continent," referring to the war in Ukraine.

Historic rivals while also fellow members of NATO, Türkiye and Greece have been at odds over issues ranging from overflights and the status of Aegean islands to maritime boundaries and hydrocarbon resources in the Mediterranean, as well as ethnically split Cyprus.

The tensions between Türkiye and Greece are also likely to come up in a potential meeting between U.S. President Joe Biden and President Recep Tayyip Erdoğan later this month, which is under discussion, Reuters reported quoting a Turkish official.

Meanwhile, Greek Prime Minister Kyriakos Mitsotakis said on Sunday during a news conference in the northern city of Thessaloniki that Athens would try to keep communication channels with Ankara open.

Deputy foreign minister Faruk Kaymakcı also touched on bilateral ties on Friday during an event organized by the Ankara-based Political, Economic and Social Research Foundation (SETA).

On Türkiye-Greece relations, he described them as "complicated" but continued to say that "if there is a will, I think there is a way."

"Greece and Greek Cypriots, they believe that they can impose their maximalist, irrational positions on Türkiye," Kaymakcı said, adding that the EU's "blind support" to Greece and Greek Cypriots due to their already being members of the EU, "complicates the problem" and does not "help anything at all."

Voicing hopes that Greece and the Greek Cypriots stop their "violations and provocations" and "focus on a positive agenda," Kaymakcı said, "we should have normal relations" and called on the EU not to meddle in bilateral issues between Athens and Ankara.

Renewed pushbacks

On the other side, the Defense Ministry on Saturday published footage of another case of Greece pushing back irregular migrants.

A Turkish navy unmanned aerial vehicle (UAV) on Sept. 9 detected irregular migrants being transferred to an inflatable boat and pushed back towards Turkish territorial waters by a Greek coast guard boat off Bodrum, the ministry said on Twitter.

"The situation was immediately reported to the Turkish Coast Guard, which rescued the irregular migrants," it added.

Türkiye has repeatedly condemned Greece's illegal practice of pushing back asylum-seekers, saying it violates humanitarian values and international law by endangering the lives of vulnerable migrants, including women and children.

Türkiye's five Aegean provinces – Çanakkale, Balıkesir, Izmir, Muğla and Aydın – are prime spots for refugees leaving Türkiye for the European Union, with Greek islands lying within sight of the Turkish coast.

In recent years, hundreds of thousands have made short but perilous journeys across the Aegean in a bid to reach northern and western Europe in search of a better life.

Hundreds of people have died at sea as a number of boats carrying refugees sank or capsized. The Turkish Coast Guard Command has rescued thousands of others.

The Turkish coast guard on Saturday said that it rescued 1,074 irregular migrants between Sept. 2-8 while arresting two suspects of human trafficking.

Türkiye and Greece have been key transit points for migrants aiming to cross into Europe, fleeing war and persecution to start new lives. Türkiye has accused Greece of large-scale pushbacks and summary deportations without migrants being given access to asylum procedures, which is a violation of international law. It also accuses the European Union of turning a blind eye to this blatant abuse of human rights.

Pushbacks are considered contrary to international refugee protection agreements, which dictate that people should not be expelled or returned to a country where their life and safety might be in danger due to their race, religion, nationality or membership in a social or political group.