NEW DELHI, July 19 -- Delhi's wave of bomb hoaxes continued for the fourth straight day on Friday, with 45 schools and three colleges receiving a mass email overnight warning of explosives planted on their campuses. Discovered by staff on Friday morning, the threat mail triggered swift evacuations, search operations, and fresh anxiety over what appears to be a calculated attempt to spread panic across the Capital's educational institutions. The email, seen by Hindustan Times, was sent from roadkillmentalhospital@atomicmail.io at 10.53pm on Thursday. Titled "Roadkill via SV Info", the message was marked to 45 schools - some of them twice - and claimed that several explosive devices (trinitrotoluene) had been planted in classrooms, hidden in black plastic bags. The message included disturbing references to suicide and anger at the mental health system, accusing psychiatrists and psychologists of failing to provide care. Police began receiving calls early Friday morning as school authorities opened their inboxes....