The Ministry of Education says a Hastings school was within its rights to close for 48 hours to hold a funeral service for a senior Mongrel Mob member.
Hundreds of gang members joined a procession on State Highway 2 on Tuesday afternoon after a service was held at Te Kura Kaupapa Maori o Ngati Kahungunu ki Heretaunga on Stock Rd, Hastings.
Several of those involved in the procession were arrested for allegedly breaching bail conditions.
National Party police and Corrections spokesman Simeon Brown said it was "unacceptable" to close the school for two days to hold a funeral for a gang member.
"The message is clear - gangs are taking greater control over every area of New Zealand society – including our schools," he added.
The ministry said the school's board made the decision to assist with the tangi because of a whānau connection the deceased man had.
Deputy secretary sector enablement and support Katrina Casey said the ministry was working with the school to make up the lost hours during the remainder of the school year.
"We're confident that the kura is ensuring that the wellbeing of its ākonga (pupils) and its wider community is its priority," she said.
The ministry said all school boards make their own decisions about how the property is used, while also considering the needs of ākonga, along with their health and safety and that of anyone else on the premises.
Police said after monitoring the situation, a team was following up reports of various traffic offences including dangerous driving and sustained loss of traction (burn-outs).
Hawke's Bay area commander Inspector Lincoln Sycamore said police have a significant amount of video footage of the procession, but would like to hear from anyone who may have recorded anything of note on SH2.
Anyone who witnessed concerning behaviour on SH2 on Tuesday is urged to contact police in person, online or by calling 105 and referencing Operation Stone.