A mother and her five-year-old daughter have been injured in a crash with a police car which was pursuing another vehicle.
It happened on Sunday close to the Sadlers Farm junction at Bowers Gifford near Basildon.
The female driver of a silver Audi A3 was taken to hospital with serious leg and chest injuries. Her daughter suffered minor neck injuries. The girl's father was injured.
Two police officers, who were travelling in a marked police BMW 530, were also taken to hospital.
Essex Police said the officers had been responding to an automatic number plate recognition (ANPR) activation. The car's blue lights and siren were on.