India, Oct. 9 -- The National Investigation Agency (NIA) has registered two separate cases to investigate suspected espionage networks in West Bengal allegedly linked to Pakistan Intelligence Operatives (PIOs), officials said.

The officials said that they are examining how Indian SIM cards were activated and subsequently used to create WhatsApp accounts operated from across the border.

The probes name four individuals from West Bengal, two of them residents of Paschim Medinipur and two from Murshidabad, who allegedly facilitated the misuse of Indian phone numbers to share sensitive information with Pakistan-based handlers.

To be sure, the federal anti-terror probe agency is investigating both cases separately, and there is no link betw...