A family friend of two teenagers recovering in hospital after they were stabbed in a seaside town centre have said they were "very lucky" to be not more seriously hurt.
Police were called to Terminus Road in Littlehampton, West Sussex, at 2.45pm on Wednesday where they found three injured boys in the nearby High Street.
A 17-year-old boy and a 16-year-old boy suffered serious injuries from being stabbed. Both remain in a stable condition at the Royal Sussex County Hospital, Brighton.
A third victim, a boy aged 16, suffered minor injuries as part of the same incident.
A 16-year-old boy, from Worthing, has been arrested on suspicion of causing grievous bodily harm with intent and remains in custody for questioning.
A Sussex Police spokesman said increased patrols were being carried out in the area and added: "The four teenagers involved are believed to be known to each other and police are continuing with inquiries this morning."
A witness, who is close to one of the injured boys, said the attack came without warning.
She told the Press Association: "I'm speechless, there was no build-up to it or anything.
"The first boy who got stabbed thought it was a punch, then realised it was a knife, then shouted out but by that time the other boy was stabbed.
"Then the other boy was stabbed in the neck. It was bleeding and he had an eight inch knife mark on his jacket.
"I saw the whole thing, chased the boys away."
She said the two teenagers taken to hospital but were recovering and added: "They are very lucky."
The witness said she did not know what prompted the fight but added: "It wasn't about drugs. I think it was over a girl, petty, one town against another, there was no way you would have known it would happen, that it would be a fight."
Police have appealed for anyone with CCTV or mobile phone footage of the incident to contact them.