SKOPJE, Macedonia (AP) — Macedonian police say they have raided 16 sites in seven cities, busting up a criminal ring that illegally dealt in coins, jewelry and other precious artifacts stolen from archaeological sites across the country.

The prosecutor's office said Saturday that 13 men were charged with dealing in goods of "exceptional value" for the country's cultural heritage. It said seven of the suspects were ordered to be kept in custody for at least 30 days while the investigation goes on.

Police spokesman Toni Angelovski told reporters Saturday that, after a yearlong investigation, police raids in seven Macedonian cities, including the capital of Skopje, led them to seize numerous coins, precious and semi-precious stones, jewelry, sculptures, ceramic and bronze items. He couldn't say exactly which eras the artifacts were from.

Angelovski said the ring had offered and sold artifacts to people in Albania, Turkey and Greece.