POLICE need help to piece together events after a crash left four injured.
Officers are specifically hoping to speak to a motorcyclist and a group of cyclists who were in the area at the time.
Police and paramedics were called to the A134 Nayland Road, Great Horkesley, just before 9am on Saturday.
A grey Volkswagen Golf and white Vauxhall Corsa collided head-on.
Firefighters from Colchester and Manningtree used specialist cutting equipment to free the casualties from their cars.
The driver of the Golf, a man in his 30s, suffered a serious injury to his foot and his two passengers were also hurt.
All three were taken to Colchester General Hospital before the passengers, two women, were transferred to Addenbrooke's Hospital in Cambridgshire for further treatment.
The female driver of the Corsa, a Colchester woman in her 50s, was airlifted to Addenbrookes Hospital after sustaining a serious leg injury.
PC Bob Colbert, said: "At the moment, we only have one independent witness to this serious crash.
"We are particularly keen to speak to a group of cyclists who were sitting on a nearby grass verge who were certainly watching the emergency services at work, but who may have also seen the moments before the collision.
"Furthermore, we know a motorcyclist drove around the smashed cars as they travelled towards the Suffolk border.
"Again, they are a key witness and would like them to contact us. We need to know what caused this crash.”
A section of the road was closed until 12:30pm while debris and oil was cleared from the road and the vehicles recovered.
Any witnesses to the crash are urged to contact Essex Police’s Serious Collision Investigation Unit on 101 or email collisionappeal@essex.pnn.police.uk
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