New Delhi, Sept. 10 -- Dr Umar Un Nabi, the bomber in last year's Red Fort terror attack, had used a "command mechanism" through a piezoelectric plate attached to his shoe to trigger the explosion, effectively making it a "foot or shoe" operated bomb, the National Investigation Agency (NIA) has claimed in its charge sheet. The claim removes the ambiguity that the bomb may have gone off accidentally as Nabi had panicked, and establishes that it was deliberately triggered at Red Fort, considered by the group as a symbol of the Indian state. The federal agency filed a charge sheet in the bombing in May this year against 10 individuals but a Delhi court took its cognizance on August 29. HT has reviewed the document. Twelve people including Nabi were killed, 29 were injured and 24 vehicles were damaged in the blast, which was carried out by a group of doctors associated with Ansar Ghazwat-ul-Hind (AGuH), an affiliate of Al-Qaida in the Indian Subcontinent (AQIS). Nabi, NIA charge sheet reveals, knew the Red Fort area very well as he had visited there multiple times. The top investigating agency has listed 12 occasions between December 2023 and May 2025 when Nabi, either alone, or with Dr Muzamil Shakeel and Dr Shaheed Saeed, visited the area. Besides, they bought electronic items for the IED from the Red Fort area....