A 14-year-old has been arrested after a spate of recent assaults in the Hawke's Bay CBD.
On 20 June, one person was left bleeding and had injuries to his head and face after an assault, Senior Sergeant Craig Vining said.
Police, with help from schools, have identified some of the young people they say are responsible.
On Friday, one young person was arrested and charged in relation to three separate assaults, including the 20 June assault.
They were due to appear in the Hastings Youth Court on 29 June.
Police said there had been several unprovoked attacks by young people targeting vulnerable members of the community.
Several 12- and 13-year-olds, identified as being involved in the recent assaults, will be referred to Youth Aid, Vining said.
"As we approach the school holidays, young people found demonstrating anti-social behaviour can expect to be stopped and spoken to by police.
"If we identify serious offences have been committed by youths, we will not hesitate to take action including the arrest and charging of offenders.
"Police are particularly concerned about the level of violence inflicted in these incidents and the 'pack mentality' of multiple persons assaulting one person."
Police said what was driving the offending was a complex issue they could not solve alone and they were focused on preventative work with partner agencies.
"Where appropriate, young people will be taken home and their caregivers spoken to about their child's whereabouts and who they are with.
"We need parents and guardians to be aware of what their children are doing and to take wider responsibility."