A man was taken to hospital with stab wounds after an altercation.
Police attended the incident on the A24 in Findon at around 7.30pm on Saturday, October 8.
Sussex Police said officers arrived at the scene to find a man with stab wounds.
Two other men had also been assaulted.
They were all taken to hospital for treatment.
Seven arrests have since been made, involving colleagues from both Thames Valley and Warwickshire police, after the suspects had left the scene prior to the arrival of emergency services.
The arrested men remain in custody and enquiries are continuing.
A Sussex Police spokesman said: “Anyone with information relevant to the ongoing investigation, particularly dash cam footage, is asked to report online, or call 101, quoting Operation Sedgemore.”
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