Four people have been arrested and 18 kilograms of cannabis grass were seized in an operation by the Drugs Squad Police which started on Monday.
The police said the cannabis was being brought into Malta from Sicily.
The people arrested are a 37-year-old man and a 36-year-old woman from Sliema, a 32-year-old man from Gżira and a 41-year-old Briton who lives in Msida.
Two have already been arraigned.
An inquiry is being held.