SKOPJE, Macedonia (AP) — Macedonian police say they have arrested 17 people, including employees in the Intelligence Agency, parliament, and interior and defense ministries, on suspicion of espionage, criminal association, blackmail and fraud.

The opposition Social Democrats criticized the operation, suggesting that the arrests were an attempt to silence critics of Prime Minister Nikola Gruevski.

Police spokesman Ivo Kotevski said Monday that those detained in raids in Skopje late Sunday and early Monday include current and former employees in the National Archives, financial intelligence service and in private companies. They are suspected of cooperating with unspecified foreign security services and handing them classified documents.

Police are searching for a further three suspects, while two more are already serving prison sentences on other charges. No further details were available on the case.