ATHENS, Greece (AP) — The crew of a Greek coast guard patrol boat fired warning shots early Thursday to deter a Turkish coast guard vessel that was trying to ram them in the eastern Aegean Sea, authorities in Athens said, as tensions between the two neighbors remain high.

Turkey’s coast guard said its crew fired into the air in response, and added that the Greek vessel was chased away.

A Greek coast guard statement said that “the crew fired warning shots in a secure sector and the Turkish coast guard vessel withdrew” toward the Turkish coast. The coast guard said the shots were fired into the air.

The statement did not make any mention of injuries, or damage to either vessel, during the incident southeast of the Greek islet of Farmakonissi and, according to the Greek coast guard, 1.5 nautical miles (1.7 miles) inside Greece’s territorial waters.

The Turkish Coast Guard offered a different version of events, saying a Greek coast guard boat harassed Turkish fishing boats off the Turkish Aegean coastal resort of Didim, prompting Turkish authorities to dispatch a coast guard boat.

The Turkish boat drove the Greek boat away from the region, enabling the Turkish fishing boats to continue with their activities, it said.

According to the Turkish account, the Greek coast guard boat opened fire into the air while leaving the region prompting the Turkish boat to respond in kind.

The incident comes as relations between Greece and Turkey, historic regional rivals and uneasy NATO allies, have been tenser than usual over the past three years.

The Greek coast guard said its vessel had been on a mission to identify three Turkish fishing boats in Greek waters off Farmakonissi. It said the Greek crew opened fire after “being harassed” by the Turkish coast guard boat, which the statement said “carried out dangerous maneuvers with the intention of ramming” the Greek vessel.

The two countries, which have come to the brink of war three times since 1974, have decades-old disputes over Aegean Sea boundaries and the war-divided eastern Mediterranean island of Cyprus.

But relations have rapidly deteriorated in recent years, with migratory flows from Turkey and offshore gas prospecting in the eastern Mediterranean adding fuel to existing distrust and historic grievances between Greeks and Turks that stretch back for centuries.

Turkish officials are also accusing Greece of militarizing its eastern Aegean Sea islands, and Turkish President Recep Tayyip Erdogan has repeatedly alluded to invading Greece in recent months. Greece counters that it needs to defend its islands against a possible Turkish attack.