Two Turkish soldiers were detained on the Greek border on Sunday after illegally crossing into the country, a defence source said.
"The soldiers are in the process of being returned to Turkey. It will probably happen today," the source told AFP, declining to comment further.
The incident near the border town of Feres comes just weeks after the release of two Greek soldiers held in Turkey since March after a similar incident.
The Greek soldiers told Turkish prosecutors shortly after their arrest that they had mistakenly crossed the border after getting lost in the fog.