Police are speaking to five boys aged 13 and 14 as part of their investigations into two assaults on West Auckland trains.
The first attack happened on February 1 just before noon on a Swanson-bound train which had just departed from Ranui station.
A 45-year-old Transdev employee was kicked and punched by six youths.
On a return trip to Ranui shortly after the first incident a 48-year-old employee was assaulted by four people who police believe were part of the same group.
Both victims required medical attention, with one suffering a fractured eye socket.
The assaults followed another attack on a train employee on January 29 at Avondale.
A 20-year-old male was arrested and appeared in the Auckland District Court on February 4 charged with wounding with intent to injure.
He entered no plea and was remanded on bail until his next court appearance on Feburary 25.
The Rail and Maritime Transport Union is calling on public transport users to leave train staff alone.
Union general secretary Wayne Butson says Transdev and Auckland Transport need to improve safety for their staff.
"They should be able to come to work, do their job and go home safe at the end of their shift," he says.
Transdev Auckland managing director Terry Scott says the assaults are extremely concerning and Transdev is taking legal advice about possible civil proceedings separate to criminal action.
Last year it increased security measures to deter antisocial behaviour by creating a security manager to liaise with police and Maori wardens.
- Western Leader
Are you happy with the council rates revaluation on your home?