The death toll in the blast near Red Fort rose to 12, with three more people succumbing to injuries, police said on Tuesday.
A powerful explosion ripped through a slow-moving car at a traffic signal near the Red Fort metro station on Monday evening. Till last night, nine people were confirmed to have died in the blast and 20 others were injured, officials said.
Police said three more people succumbed to injuries taking the toll to 12.
Delhi Police on Tuesday registered an FIR under the Unlawful Activities (Prevention) Act and the Explosives Act in connection with the deadly blast.
Raids are being conducted at multiple locations by Delhi Police. The national capital has been placed on high alert with strict vigil being maintained at the airport, railway stations and bus terminals.