Police are appealing for witnesses after a man was taken ill and died following an assault at a Burgess Hill cafe.
A group of people were working late at around 11.20pm on Friday at the cafe in Church Road - which was due to open the following day - when trouble started.
Four people, who the cafe workers did not know, caused a disturbance. Sussex Police say during this time a 35-year-old woman was assaulted.
The altercation spilled out into the street and a car, believed to be a small silver car possibly a Toyota Aygo, had to stop.
The group then left the area.
Police said shortly afterwards, one of the people from the cafe, a 64-year-old man from Burgess Hill, collapsed and was taken to the Royal Sussex County Hospital, where he later died.
Detective Inspector Sarah Barrett said: “We are appealing to anyone who was in the Church Road area and might have seen what happened.
“We are also specifically appealing to the car driver which had to stop as they might be able to give us a description of those involved.”
She said the man who was taken to hospital and later died was not assaulted himself and that doctors believed he might have suffered a seizure or a heart attack.
A post mortem is now to be held on the man who died around lunchtime on Sunday, having previously been described as being in a very serious condition when he was first admitted to hospital.
Detective Inspector Barrett said: “Two people have been arrested at this time and we are trying to identify two other men who were also involved.”
Sussex Police say two 19-year-old men from Haywards Heath have been arrested on suspicion of causing grievous bodily harm with intent.
They have been released on bail until July 15 while enquires continue, say police.
Anyone who saw what happened or has any information is asked to contact police on 101 quoting Operation Abraham.
Alternatively, you can call the independent charity Crimestoppers anonymously on 0800 555 111.