Police in The Hague have arrested 31 people in a long-running investigation into drugs in the region, news agency ANP reports on Monday.
The probe began last year and four people have already been jailed in connection with the case. Six others face charges and 19 have been released but are still considered suspects, news agency ANP said.
Police seized some 5,000 ecstasy pills and 150 kilos of cocaine during the investigation.
The gang is also suspected of being behind the theft of €100,000 worth of flowers from the Naaldwijk flower auction at the beginning of this year. Police think the aim was to hide drugs in the flowers so they could be more easily exported.
The investigation involved officers from several different forces as well as customs officials and the coastguard. Some 14 properties were searched where guns and ammunition, cash money and expensive watches were also impounded.