They said the drugs cache, which had been concealed inside a container of frozen fish and was uncovered during a scan, had an estimated street value of €7m.
The drugs haul is one of the largest to be uncovered in Morocco this year. In April, 9 tons of cannabis resin destined for France was found at the kingdom's economic capital, the port of Casablanca.
And just last week, also in Casablanca, customs officers sniffed out a 4 ton consignment of the same drug bound for Belgium.
Customs officers in Morocco, a major producer of hashish, say they are equipped with "sophisticated detection" equipment for the fight against narcotics trafficking.
Since 2007 Moroccan authorities have battled trafficking in the country's northeast where the cultivation of kif, or hashish plants, has been reduced from 130 000 to about 56 000ha, official figures show.
- SAPA
