The incident occured at around 9:30 am on the Kharar- Kurali road, police said.
"Four children were going to the Nirankari Bhawan here by crossing the road when they were hit by a car," Kharar police (City) Inspector, Satnam Singh said.
The deceased were identified as Manvir (8), Ritu (12), (brother and sister) and Nikhil (10), Singh said.
The injured child was identified as Khushboo (15), the sister of Manvir and Ritu, according to the police.
The deceased were residents of Bhukhari village in Kharar. The police have registered a case under relevant sections of the IPC against an unknown driver, the official said.