Teenagers have been arrested in connection with the murder of a 40-year-old man.

The victim, who lived in a flat above a shop in the High Street, Hailsham, is believed to have sustained serious injuries during an assault by a gang of youths. He later died in hospital.

Launching a murder inquiry, police initially dismissed suggestions that the attack might have links to a "yob culture" said to have invaded the quiet town.

But locals spoke of a place where in recent years there had been attacks of vandalism by groups of young people who had taken to hanging round on the streets. Some people now claimed the town centre had become a "no-go" area at night.

The attack happened on Sunday at 9.30pm in the precinct centre.

The victim was taken by Sussex Ambulance to Eastbourne General Hospital, where he was pronounced dead. As The Argus went to press, the man had not been named. A post mortem was expected to be carried out yesterday.

Neighbours said they thought the victim had moved in recently.

Police would not reveal details of how many teenagers had been arrested for fear this could jeopardise their inquiries.

Detective Chief Inspector Tony O'Donnell, from Sussex Police's major crime branch, who is leading the investigation, said: "Although we are at the early stages of our investigation, we believe this incident was not a random attack and that the victim and the offenders were known to each other.

"We have identified about six youths who we believe to be involved and, although we are still trying to establish a motive, one possibility is that this was a result of an altercation over a relationship."

Yesterday Hailsham was still reeling from news of the murder.

A police investigation tent had been set up around the back of the flat where the man was believed to live and officers had cordoned off a large area including the back of the property and an adjacent churchyard.

Police were conducting a fingertip search of the churchyard and were expected to examine CCTV footage of the incident from one of the town's cameras, which was pointed directly at the spot where it took place.

Bank holiday activity carried on as usual but the mood was sombre as people spotted the police presence and cordons surrounding the precinct.

A woman who lives in the High Street and works in the Grenadier pub said an hour after the gruesome attack she and her family walked close to the scene on their way home from a barbecue.

She said: "It's scary to think something happened so nearby but we didn't see a thing when we were walking back with the kids.

"Everyone is really shocked. They just can't believe what happened. Lots of people have been in today. We're just in shock."

Others reported there had been an increase in the number of youths gathering on the streets in recent years. Most did not want to be named for fear of reprisals.

A woman who works in Boots in the precinct centre said: "It's terrible. I have to come into work really early in the morning and walk through here and now it makes me jittery to think I have to come up here on my own."

Her friend said: "I wouldn't come up here at night on my own any more. None of us would."

She said the problem of gangs of youths had been going on for about a year.

She said: "It has always been a nice quiet sort of town up until recently. We just don't expect this. It has been getting worse over the last few months."

A woman who works in the Cancer Research shop in the High Street said: "People have been coming in saying there are reports of gangs of youths around here. One lady said her son was sprayed with gold paint. A lot of customers have been saying there have been problems."

Bill George, 68, is treasurer of Hailsham Club, just yards from where the incident happened.

He said: "There is a mob who hang around here. They just cause general vandalism but there's never anything like this. They are teenagers with hoods.

"We close here at 11pm but usually the trouble is later. Benches have been lifted up out of the ground and windows get smashed along the High Street. Sometimes things are thrown from roofs.

"They should be shut in at night. They can't do all of those things if they're not allowed out. They don't worry me but there are some people that are intimidated.

"Up until two years ago there wasn't a problem. It always seems to be the same group but it's a shame all the youths get tarred with the same brush. I believe this group is known to the police."

Ray Waltonby, 32, said: "I don't live in Hailsham but I come here quite often. I can't believe what's happened. I think it's awful. Now it seems these thugs are getting away with murder."

One woman who has lived in Hailsham for 40 years said: "It's absolutely dreadful. It's awful and I'm appalled. The atmosphere here today is so sombre. It's very disturbing. Nothing like this has ever happened here before and I hope they find them."

James Goacher, 25, of High Street, said: "I moved down from south-east London to get away from this kind of thing and now it's happening again.

"It's not the sort of thing you'd expect in a quiet place like Hailsham. I think the whole area is just getting worse. I don't think anyone is safe any more nowadays. Crime is getting out of control."

A local man, 55, said: "I drove through this morning and saw the police and realised there had been some trouble but nothing like murder. It's so out of character for the town.

"There is all this talk about social unrest but this is unacceptable. The town centre is a place for people to meet socially. It defies belief."

Ricky Hay, 61, from Hailsham, said: "They run amok here of an evening. If you walk through the town centre, you are taking a chance and there are no police about to help you. This used to be a pleasant little town but it has changed so much."

Teaching assistant Martin Tillman, 55, said: "There are so many gangs of lads around of an evening and there is always vandalism taking place. It is a no-go area and people keep out of town."

He added that the police presence was not high enough to deter rowdy gangs of youths from congregating in the town centre.

"Very, very rarely do you see a foot patrol and there is no way you will stop that kind of thing by driving through in a car."

Mother Sue Burton, 43, said that there was a lack of activities for teenagers in the area. She said: "There are kids that hang around but this is surprising for Hailsham to be honest."

A police spokeswoman said those arrested were in their late teens but she would not say how many were being questioned.

She said: "There have been some arrests of people in their late teens who will be questioned overnight.

"This is being treated as a major incident. Police are now trying to track down further key witnesses to help them with their inquiries."

Police are appealing for anyone who was in Hailsham High Street on Sunday night to contact them on 0845 6070999 quoting Operation Aircraft.