Spanish police say they have arrested 14 suspected drug smugglers and confiscated 3,700 kilos of hashish in a drug bust in southern Spain.

Police said Saturday they also confiscated three speedboats, a fishing boat and a yacht they suspected the gang used to smuggle the drugs from Morocco to the Cadiz region of Spain across the Strait of Gibraltar.

The police say the arrested suspects include the two leaders of the ring, who "handled contacting the Moroccan (drug) suppliers."

The police operation began in November 2016. Police arrested two alleged members in February, four more in March, and the remaining eight at a later unspecified date.

The Cadiz province, 14 kilometers (8.6 miles) from North Africa, amounts to 40 percent of the drugs entering Spain, according to Spain's Interior Ministry.