MADRID, August 4, 2008 (AFP) - Spanish customs authorities said Monday they arrested three Dutch citizens and seized 3.8 tonnes of hashish on a yacht, in a 'major operation' against drug trafficking into the European Union.

A total of 127 packets of cannabis resin were found Saturday on the Dutch-flagged yacht in international waters off northwestern Spain, the customs service said in a statement.

The three Dutch crew members were arrested, in what it described as 'a major operation against drug trafficking into the European Union.'

Spain, with its extensive coastline, is Europe's main point of entry for Moroccan cannabis and for cocaine from South America, mostly from Colombia.