SKOPJE, Macedonia (AP) — Macedonian police say 166 artifacts, including gold and silver jewelry, dating from the 4th century A.D. have been stolen from storage in the country's biggest museum.

Police said Tuesday that an organized crime ring is thought to be behind the theft, and the antiquities are believed to have been sold abroad.

Authorities are still uncertain when the pieces were taken from the Museum of Macedonia in central Skopje. Last month, curators reported that 60 artifacts, mainly earrings, pendants, rings and bracelets from two cemeteries in central Macedonia, had gone missing. They later added another 20 artifacts to the list.

Police spokesman Ivo Kotevski said a full investigation raised the number of missing artifacts to 166. He said museum employees are being questioned.