Bengaluru, Dec. 4 -- The National Investigation Agency (NIA) has intensified its probe into the deadly car blast near Delhi's Red Fort, returning to Bengaluru's Parappana Agrahara Central Prison for a fresh inspection after preliminary findings indicated that a suspected terrorist lodged there may have used an illegal mobile phone in the run-up to the attack.

The agency's second visit to the high-security facility comes amid mounting concerns over a viral video that recently showed terror accused Juhad Hamid Shakeel Manna and several rowdy sheeters freely using mobile phones and availing prohibited amenities inside the prison, raising serious questions about security lapses and internal complicity.

Thirteen people were killed and more tha...