Police say they have arrested four Greeks for trying to sell two religious icons and a golden cross dating to the Middle Ages for $7 million.

The arrests follow a sting operation in which an undercover officer posed as a prospective buyer. Police say the icons — religious paintings on wood — represent Greek Orthodox saints. All three artifacts were confiscated.

Under Greek law, ancient and medieval artifacts are state property. Their sale by all but a small number of licensed traders and collectors is strictly prohibited.

Police said Thursday a large number of other antiquities were confiscated in raids on the homes of the suspects in the town of Serres.