CRPF schools in Delhi and Hyderabad safe after hoax threat email; security agencies investigating potential Khalistani involvement.

The sender linked the threat to the arrest of suspended former DMK leader Jaffar Sadiq, first by the NCB and then by the ED. He also claimed that Sadiq's arrest led to an internal rift in the Tamil Nadu Police.

Officials from the Institute of IED Management in Pune, the Forensic Science Laboratory (FSL), and security personnel conducted investigations at the site

The threat email comes a day after a blast along the boundary wall of the Central Reserve Police Force (CRPF) school in Prashant Vihar area of Rohini in the national capital. Security and intelligence agencies are probing the role of Khalistani supporters in the Sunday morning blast.

The hoax threat against CRPF schools comes at a time when similar threats have been issued against over 100 flights since October 14.

A FIR has been lodged following an explosion outside CRPF Public School in Rohini, northwest Delhi, causing damage to the school's wall, nearby shops,

The schools affected by the hoax threats include two in Delhi--one in Rohini and another in Dwarka--as well as one in Hyderabad.