SKOPJE, Macedonia (AP) — Macedonian police say they have seized half a million tablets of synthetic drugs from a laboratory in the west of the country, and arrested six people suspected of drug production and trafficking.

Interior Minister Oliver Spasovski says Thursday's seizure came in a joint operation with Serbian police and the U.S. Drug Enforcement Administration.

He says five locations were raided in the capital, Skopje, and the western town of Tetovo.

Spasovski said Friday that the haul was the biggest of its kind in the Balkans, and the drugs seized, which weighed a total 125 kilograms (275 pounds), have an estimated market value of 2.5 million euros ($3 million). They would have been sent to Turkey.

The suspects are Macedonian and Serbian nationals.

Spasovski didn't specify the type of drugs confiscated.