Authorities said the suspects were members of the Jamaah Ansharut Daulah (JAD), which has links with the self-proclaimed Islamic State (IS).
According to local media, seven of them were captured in Bekasi, and the other was caught in Cilincing district, northern Jakarta.
Spokesperson of Jakarta Police Argo Yuwono said that Densus 88 confiscated explosives and bomb-making materials during raids conducted the same day, revealing that the suspects were planning a terror attack.