A coastguard statement today said the operation, which followed a tip-off, was carried out in coordination with the US Drug Enforcement Administration.
The suspects, who were arrested late yesterday, were identified as six Greeks and five foreign nationals. The coastguard wouldn't specify the nationalities further and it wasn't immediately clear where the heroin had come from.
It said the drug ring had operated from a warehouse east of Athens and distributed the heroin in trucks to Greece and other European countries.