Police Scotland were yesterday granted a "period of extended detention" for a "number of individuals" who are being detained under the Terrorism Act 2000.
The suspects have been accused of "committing various offences" and were arrested on Wednesday at "several locations".
Police confirmed those detained were "individuals sympathetic to dissident Republicanism".
However, they are not affiliated to any specific group.
It is not clear what time extension police have been granted in relation to the detention.
A spokeswoman said: "Police Scotland has been granted a period of extended detention in respect of the individuals arrested on Wednesday October 23 under the Terrorism Act (2000)."
Police Scotland said it was unable to provide further detail, including how many were arrested or in which areas of the country they were detained.
The operation involved the Police Service of Northern Ireland and the Security Service.
Assistant Chief Constable Ruaraidh Nicolson, who confirmed the arrests earlier this week, said: "We are confident as a result of these arrests there is no risk to the public."
Section 41 of the Terrorism Act 2000 allows police to arrest anyone they "reasonably suspect" to be a terrorist.