Some 72,000 residents in the Thessaloniki-area Kordelio district were being evacuated on Sunday from a perimeter 1,900 meters around where a WWII-era bomb was discovered.
An effort to neutralize the munitions began at 6 a.m. (04.00) GMT, with Hellenic Army bomb disposal technicians set to begin the operation at roughly 10 a.m.
Police have sealed off the area up to 30 kilometers.