New Delhi, Nov. 28 -- A Delhi court on Thursday remanded four persons in police custody for two days in connection with the November 23 protest against air pollution near India Gate that allegedly turned violent, ruling that custody was required but not for the full period sought by investigators.

"Considering the nature of allegations, the stage of investigation, recovery of digital devices and the need for confrontation, identity verification and device examination, this court finds police custody remand necessary, though not for the period requested," judicial magistrate Sahil Monga said in the order.

Meanwhile, investigators have revealed that the seized phones of arrested students contained "auto-delete" features and formatted data...