Two Greek soldiers held hostage by Turkey

Two Greek soldiers are being held by Turkish authorities after they allegedly crossed the border. They are now to be tried for espionage, as Turkey seeks the return of eight officers who escaped to Greece after the failed coup. Greece has refused to return them and now this new issue seeks to link the two separate cases.
Did the officers cross into Turkish territory, or were they captured on Greek territory as the area where the incident happened?
President Pavlopoulos of Greece gave a statement stating the following: “We might not have had the territory we should have had historically. If history compels us, we will do what our ancestors have done.”
Hami Askoy, σpokesperson of the Turkish Ministry of Foreign Affairs, stated in response: “we invite President Pavlopoulos to respect international law and our borders and to refrain from a rhetoric which is not befitting his position and that could could cause unnecessary tension.”