India, March 23 -- What began as a routine intelligence alert in Ghaziabad has snowballed into one of the most serious espionage cases in recent years, exposing a Pakistan-linked network engaged in pre-attack reconnaissance across India.

At least 22 people, including several minors, have been arrested so far after suspicious activity was flagged at the Kaushambi police station on March 14, media reports said.

Initial inputs indicated that youths were filming railway stations and military installations in Bhovapur, but investigators soon uncovered a far more organised operation.

A Special Investigation Team (SIT), comprising personnel from Indirapuram Police, Crime Branch, cyber units and intelligence agencies, was formed.

Interrogatio...