Greek fishermen allege they were threatened and had warning shots fired at them by crews on Turkish fishing boats during a tense confrontation in the Aegean Sea on Tuesday night, a local union leader said.
Giannis Manios, president of the Kavala fishermen's association, told Greek media that dozens of Turkish vessels had approached within a few miles of the island of Samothraki.
When about 20 Greek boats sailed out to protest their presence, Mr. Manios claimed they were met with insults and gunfire.
The Greek fishermen, who filmed parts of the encounter, eventually retreated and returned to the port of Keramoti, where Mr. Manios said they would stage a work stoppage in protest.
He alleged that Greek authorities were notified of the incident but did not intervene. Videos shared on social media also appeared to show Turkish coast guard vessels harassing the Greek boats.
The incident is the latest flashpoint in the long-standing maritime dispute between Greece and Turkey in the Aegean Sea, where fishermen are often on the front lines of competing territorial claims.