A 12-year-old boy has died and five others were injured in a "deliberate" hit-and-run crash near a school.
The crash happened near Debden Park High School in Loughton, Essex, at about 15:20 GMT.
Two 15-year-old boys, a 13-year-old boy, a 16-year-old girl and a 53-year-old woman were also hurt but their injuries are not believed to be life-threatening.
Police have launched a murder inquiry and want to speak to Terry Glover, 51.
Ch Supt Tracey Harman, of Essex Police, said officers were looking to speak to Mr Glover, from Loughton, "in connection with the investigation".
Ms Harman said officers were investigating whether the crash was linked to "another incident nearby" and made a "direct plea" to Mr Glover to contact police.
Where is Terry Glover??? We urgently need to speak to him in connection with today’s incident in #Loughton any sightings or information to his location please contact @EssexPoliceUK urgently on #999 pic.twitter.com/WZjk2eEfBR— Insp Rob Brettell (@InspBrettell) December 2, 2019
The force has appealed for help locating a silver Ford KA, with registration number LS08 OKW, which was "likely to have damage to [its] front" and failed to stop at the scene.
It is thought all the injured children were also pupils at the school on Willingale Road.
A 15-year-old boy who was hurt told the BBC he believed the driver had deliberately targeted the group.
Speaking from an east London hospital, he said he was walking on the pavement with a friend when he heard a car revving behind him.
He described how the Ford KA sped up, mounted the pavement and hit the pair of them, throwing his friend over the bonnet.
The GCSE student, who is awaiting treatment for injuries to his arm, back, leg and head, said all those hit by the car were walking near to him.
Debden Park's head teacher Helen Gascoyne said she was "devastated" to confirm the boy who died was a student at the school.
She said: "It is with great sadness that we must report that a 12-year-old student from our school has sadly died.
"Our thoughts are with the family and all those affected....The school will be open tomorrow with a number of counsellors on hand to support our community."
Det Ch Insp Rob Kirby, of the Kent and Essex Serious Crime Directorate, called the crash "truly shocking" and appealed for dash-cam footage.
"I would like to thank the many members of the public who have called us with information and spoken to our officers, as well as those who provided crucial medical assistance at the scene," he added.
Insp Rob Brettell said: "We are trying to locate and find a silver Ford KA which is likely to have damage to the front of the car."
He urged anyone who has seen the car or knows where it is to contact the force, and said it was likely to be a "prolonged and serious investigation".
Willingale Road cannot be accessed from junctions on either side of the school and the area remains cordoned off.
Sebastian Fontanelle, who lives near the scene of the crash, said police arrived "rapidly" and he saw the air ambulance land at about 16:00.
Father Sam Stuart said St John's Church in Loughton would also be open on Tuesday "for prayer, lighting candles and if anyone needs to talk".