Cannabis worth £1m has been seized in south Belfast, police have said.
A 37-year-old woman was arrested in Stranmillis, and a 48-year-old man in the Lisburn Road area on Thursday.
Police said the drugs were found during searches as part of the operation. They are continuing to question the man and woman.
Det Insp Pete Mullan said the operation was "evidence of our ongoing commitment to removing and disrupting the illegal supply of drugs into Northern Ireland".
Det Supt Bobby Singleton told BBC News NI the seizure represented the culmination of an investigation which had run for some time.
Gaps in postal system
He said the PSNI was of the view the drugs had come from somewhere in Europe, possibly the Republic of Ireland.
Det Supt Singleton said that while in some cases drugs are smuggled, criminals are also using other methods.
"We've seen an increase in the use of fast parcels and the postal system as a means of bringing in a variety of drugs.
"In some cases it's intercepted but it also remains the case that there are some vulnerabilities within that system.
"We are working with a variety of partner agencies including the National Crime Agency (NCA) and UK border force to try to close those gaps".
He described cannabis as "the backbone of the drugs economy in Northern Ireland".
"It's what makes it profitable for organised crime groups to work in this area, therefore focusing on this is a key part of our strategy," he said.
"This find will have been a significant blow to them."