Greek police say they have stopped a truck with stolen license plates and found 59 undocumented migrants inside.

The truck was stopped Friday afternoon on the highway about 30 kilometers (20 miles) east of Thessaloniki, because it had Bulgarian license plates that had been reported stolen. Behind a few boxes of insulation materials lay the 59 migrants, about half from Somalia and the rest from Afghanistan, Bangladesh, Egypt, Eritrea, Iraq, Palestine and Sudan, police announced Saturday.

The migrants told police they had paid 1,500 euros ($1,690) each to a trafficker in Turkey who helped them cross into Greece by boat, before boarding the truck.

The 61-year-old Bulgarian driver was arrested.