New Delhi, June 14 -- Police on Sunday apprehended four people, including a 17-year-old girl, for allegedly setting a scooter on fire over a financial dispute, an act that allegedly triggered a blaze and explosion in a residential building in southeast Delhi's Tughlakabad Extension, killing three members of a family in the early hours of Friday.

Police said CCTV footage showed the minor entering the building with her face covered with a dupatta shortly before the blast and then quickly exiting the premises, all within a few minutes.

Police have added charges of criminal conspiracy, culpable homicide, attempt to commit culpable homicide, mischief by fire, and house trespass to the first information report (FIR) that was registered at the...