A teenage boy was left in intensive care in Altnagelvin following an assault in the Waterside on Saturday.
Police attended the report of the assault in the Violet Street area at 7pm on December 16.
Detective Sergeant Brian Reid said: “A 16 year old boy was treated in hospital for a number of facial and head injuries. He is currently in intensive care, in a stable condition.
“His injuries are not thought to be life-threatening at this time. A second man, aged 22, suffered a suspected broken nose.
“Two males, aged 17 and 23, were subsequently arrested on suspicion of grievous bodily harm with intent; and assault, occasioning actual bodily harm. They are currently in custody, helping police with our enquiries.
“We are appealing to anyone who has information about this incident to contact detectives at Strand Road on the non-emergency number 101, quoting reference 1425 of 16/12/17.
“Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111 which is 100% anonymous and gives people the power to speak up and stop crime.”