A 13-year-old boy has been arrested on suspicion of attempted murder following an attack which left a man fighting for his life.
The 46-year-old victim was kicked, punched and left unconscious with serious head injuries after an altercation with a group of teenage boys outside Premier convenience store in The Hydneye, Eastbourne just before 9pm on Thursday, said a Sussex Police spokesman.
South East Coast Ambulance Service staff tended to the man, who is now in a critical condition at Eastbourne District General Hospital in East Sussex.
Detective Chief Inspector Nick May, from the Surrey and Sussex major crime team, said: "I am appealing to anyone who was in the area of the Hydneye between 7pm and 10pm and who may have information about this violent assault to contact us. In particular, did you notice a disturbance or a group of teenagers causing a nuisance outside the Premier store during that time?
"This was a vicious attack which has left this man fighting for his life. There were a number of people in the area at the time. If you know who these teenagers are, or have any details that may help our investigation, please contact police."
Chief Inspector Jayne Dando, Eastbourne district commander, said the community is shocked by the attack.
"My neighbourhood officers know the community well. Over the coming days we will be available to address concerns that residents may have and reassure them that such a violent incident is very unusual," she said.
"We will continue to be visible and will be working tirelessly to keep people informed about what we're doing and to gather any information that could prove useful."
Anyone with information about the attack can call Sussex Police on 101 or Crimestoppers anonymously on 0800 555 111.