Police said on Friday that officers have made the biggest drug seizures of the year for both cocaine and cannabis.

Officers raided six drug storage warehouses belonging to the same syndicate in Kwun Tong, Hung Hom, Kwai Chung, Lai Chi Kok, and To Kwa Wan between Wednesday and Friday.

Police seized about 592 kilogrammes of suspected cocaine and about 91 kilogrammes of suspected cannabis.

The drugs are believed to be worth around HK$650 million.

Four men aged 25 to 32 were arrested and charged with trafficking dangerous drugs.

"We believe that the drop in the price of cocaine has attracted local criminal groups to seize this opportunity to stockpile large amounts of cocaine for supply to the local market," Chan Kong-ming, a senior superintendent in the narcotics bureau, said.

"[The syndicate] spared no expense to constantly rent different warehouses to store drugs and minimise the risk of getting caught. They stockpiled a large quantity of drugs to have the flexibility of distributing them in batches in the future," he added.

The syndicate shipped the suspected cannabis along with frozen fish products into the city to mask the smell of the drug, the force added.

The case will be mentioned at Kwun Tong Magistrates' Courts on Saturday.