People living within two kilometres of the site where the Antonov-12 came down have been warned to stay indoors.
The aircraft was flying from Serbia to Jordan when it crashed late on Saturday close to the city of Kavala, killing all eight people on board.
Eyewitness video showed the plane on fire and a huge fireball as it crashed.
Drones were used to survey the site of the wreckage out of caution, while Greek state-run TV reported the army, explosives experts and Greek Atomic Energy Commission staff were not approaching the site until it was deemed safe.
