Uttar Pradesh Special Task Force and Anti Terrorism Squad have detained ISIS suspect from Bihar's Narkatiaganj area.
The Delhi Police Special Cell has arrested three ISIS suspects from Jalandhar, Mumbai and Bijnor in a joint operation with the Uttar Pradesh Anti-Terrorist Squad.
The Uttar Pradesh Anti-Terrorist Squad said it received information of a group being readied for terror activities.
"Special Cell Delhi Police, CI cell Andhra, Maha ATS Punjab and Bihar Police were involved in the operation," it added.
Legal action would be taken based on evidence.
Meanwhile ADG (Law and Order) Daljeet Singh Choudhary told ANI, "Nine people from different locations were held by police. We have evidence against four such people, all are self motivated/radicalized; not in liaison with any group."
He further said, "In the searches conducted, no incriminating evidence has been found as yet. But it can be called a possible criminal conspiracy."