Speaking to Tasnim on Sunday, deputy prosecutor general of the city of Mashhad, Judge Hassan Heidari, said the number of suspected members of ISIS arrested in the province over the past days has risen to 27.
The intelligence forces expanded their investigation in the cities of Khorasan Razavi Province hunting for clues, and arrested more suspects in recent days, he added.
On Thursday, Heidari had announced the arrest of 21 Takfiri ISIS terrorists in the holy city of Mashhad.
He had noted that the detainees, including Iranian and Afghan nationals, had plans to carry out different operations in Iran, including suicide attacks.
There has been a surge in the number of counterterrorism operations the Iranian security forces have launched in recent weeks.
The Intelligence Ministry has arrested dozens of militants affiliated with the ISIS terrorist group across Iran following the June 7 attacks in Tehran that were claimed by the Takfiri group.