The incident happened on the Mehrauli-Badarpur route.
A five-year-old girl and her seven-year-old brother were killed and their grandfather critically injured after a cluster bus ran over them in south Delhi, police said on Wednesday.
The incident happened on the Mehrauli-Badarpur route when Bhagwan Paswan was crossing the road with his two grand kids- Rishika and Sailesh- while taking them to their MCD-run school in Saket G-Block, a senior police officer.
The cluster bus - the orange colour bus - on route 717 hit them at about 8 am, police said.
Rishika died on the spot while Shailesh and Paswan sustained severe injuries, said the officer.
Sailesh was first rushed to Max Hospital and later shifted to AIIMS, where he died.
Paswan is undergoing treatment at Max Hospital, Saket. The accused bus driver had fled the spot but was later arrested.
The victims are residents of Saidullajab in South Delhi. Their relatives, accompanied by locals, staged a protest and blocked the Mehrauli-Badarpur road disrupting traffic for nearly half-an-hour.
The police had to use mild force to disperse the crowd.