NEW DELHI, May 7 -- Two friends were killed and two others sustained injuries late on Saturday in the Delhi Cantonment area after a speeding car hit their motorbike, police said on Tuesday, adding that the errant driver has been arrested. Police identified the deceased were identified as 19-year-old Mangal Kumar and 20-year-old Vikas Kumar, and the injured as Raja Kumar and Sahil Kumar. Raja is currently being treated in the hospital. An investigator said that the deceased were residents of the Dhobi Ghat area in Kirby Place. Police said the car driver, Rakesh Kumar, was arrested from the spot. Kumar serves as a corporal in the army and was returning home at the time of the accident. None of the four friends on the bike had helmets on and h...