A 75-year-old man has died after he confronted three teenagers who were causing a disturbance outside his home.
The elderly man confronted the youths outside his home
A number of alleged assaults took place after the man and some of his family tackled the youths in South Coast Road, Peacehaven on Friday evening.
The scuffle continued at a bus stop close to the house and the man collapsed and died soon afterwards.
Sussex Police said three teenagers were first arrested on public order offences and later on suspicion of manslaughter.
The youths were aged 15, 16 and 18.
It is thought the 75-year-old man was Portuguese and married.
His neighbour's son, who did not want to be named, said: "He was a good neighbour to my dad. Always having a chat and a drink together."
Det Insp Till Sanderson said the exact circumstances of the incident were unclear.
"This is a tragic incident and our thoughts are with the family," he said.
"In order to help us understand the full circumstances I would urge anyone who witnessed it to contact police."
A post-mortem examination is expected to take place on Sunday.