Eight men and one woman have been arrested as part of a cross-Border operation targeting drug dealing linked to paramilitary group the INLA.
The suspects, aged between 27 and 42, were detained in Derry and Limavady on Wednesday and Thursday, the Police Service of Northern Ireland (PSNI) said.
The woman has since been released on bail while all of the arrested men remain in custody.
Raids were carried out on both sides of the Border as part of a year-long joint operation involving the PSNI and the Garda.
In the North, a “significant” quantity of cannabis, suspected class A controlled drugs, drugs paraphernalia and a “substantial quantity” of cash in euro was seized.
In the Republic, gardaí searched seven properties in Kerrykeel and Buncrana in Co Donegal, as well as in Finglas, north Dublin, on Wednesday.
A number of electronic devices were seized.
PSNI Det Chief Supt John McVea linked the operation to the Irish National Liberation Army (INLA).
“The INLA in the northwest are involved in all forms of criminality including the organised illegal supply of controlled drugs,” he said.
“This operation looks to take action against those involved in this illegal drugs supply. These criminals don’t care about the wider impact their drug dealing will have on the wider community and public services.
“They do not care about the harm and devastation they cause, all they want is to make money by whatever means they can. They prey on the most vulnerable in our communities, using fear and intimidation, callously exploiting people’s vulnerabilities in the most despicable ways possible.
“The money they take from people who may be struggling financially, is used to line their own pockets and feed their own greedy needs.”
Det Chief Supt McVea said the INLA “use violence indiscriminately to control the community, stopping people giving information to police, leaving them free to exploit ordinary people in the areas where they operate”.
Garda superintendent Goretti Sheridan said the cross-Border operation into INLA drug dealing on both sides of the Border had been ongoing since last summer.
"This is a borderless crime and is imperative we in An Garda Síochána work closely with our colleagues in the PSNI in order to combat the sale and supply of controlled drugs which are devastating our communicates," she said.
“The INLA like other gangs involved in drug dealing are making huge profits and benefitting from this legal activity.”