Police are investigating reports of a disturbance and a suspected gunshot in the Sidley Green area of Bexhill at about 11.50pm on Monday, 8 June.
Officers, including armed officers and a police dog unit, attended the area and enquiries remain ongoing to establish the full circumstances of the incident. No injuries have been reported to police in connection with the suspected gunshot.
A black Nissan Qashqai was subsequently pursued by police and was involved in a serious collision in Ivyhouse Lane, north of Hastings, during the early hours of Tuesday, 9 June.
Four occupants of the vehicle sustained injuries. One person was airlifted to hospital, where they remain in a serious condition.
The driver of the vehicle, a 26-year-old man, of no fixed address, was arrested on suspicion of causing serious injury by dangerous driving.
The three passengers, a 21-year-old man from Bexhill, a 23-year-old man from Bexhill and a 36-year-old man from St Leonards, were arrested on suspicion of affray.
All four men remain in hospital, where they are under police guard.
T/Detective Superintendent Jay Mendis-Gunasekera said: "This is a fast-moving investigation and we are working hard to establish the full circumstances of both incidents.
"We understand the concern this will cause within the community and there will be an increased police presence in the area while enquiries continue.
"We are particularly keen to hear from anyone who was in the Sidley area around the time of the reported disturbance, or who may have CCTV, doorbell, mobile phone or dashcam footage that could assist our investigation."
Road closures remain in place in Ivyhouse Lane between Chowns Hill and the crossroads with Moor Lane and Rock Lane near Three Oaks while collision investigation work continues.
Anyone with information is asked to report it online or call 101, quoting Operation Maxim.
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