Charlie Preston and his friend Frankie Gater, both 16, were killed when they were ambushed in the early hours of Sunday. Charlie's mum Kirsti, 37, who has two other children, reportedly told a friend: "I am broken. I don't know how I'm going to be able to deal with this. I have lost my firstborn child." She wept when she visited the scene of her son's death on Monday.

       The friend said: "I have spoken to Kirsti, she is broken. I have spoken to Charlie's gran, she is in pieces. And I have spoken to Kirsti's sister, they are all in shock and disbelief. It is so sad, tragic."

       Charlie and Frankie were stabbed in Brentwood, Essex. A third victim suffered non-life-threatening injuries. Neighbours said the site, near the centre of the prosperous town, was notorious for anti-social behaviour.

       Detectives are working on the theory the attack was targeted and that those involved knew each other. Eight men were arrested on suspicion of murder. Last night, three suspects, aged 19, 20 and 21, were still in custody.