A series of searches have taken place in north, south and east Belfast, Larne and Co Down.
More than 17 kilos of high quality cannabis, which was packed and believed to have been imported, have been seized.
A 45 year old woman was arrested in east Belfast and a 24 year old woman was arrested in south Belfast.
They are being questioned at a police station in the city.
Detective Chief Inspector Douglas Grant, from Organised Crime Branch, said: “As well as the imported cannabis, officers have seized cash, documents, drugs paraphernalia and a computer.
“We have taken a substantial quantity of drugs out of circulation and reduced the harm they cause to communities in our towns and cities.
“We will continue to work with our colleagues in District policing and with local communities to bear down on those involved in the illegal drugs trade.
“We would encourage anyone with information about such activity, in any part of Northern Ireland, to contact police.”