A fight at Splash Planet on Sunday ended with two staff members being taken to Hawke's Bay Hospital with head injuries.
A witness, who did not want to be named, told Hawke's Bay Today the incident was sparked by an argument at the Hastings water theme park's bumper boat dry ride
attraction just before midday.
Two staffers in charge of the ride had asked two teenagers to leave the park and a fight broke out.
An adult, believed to be a parent of one of the teens, became involved and witnesses were threatened against talking to the police.
Police arrived and two youths were arrested but were later released without charge. The two Splash Planet employees were admitted to Hawke's Bay Hospital with head injuries.
Hastings Police Senior Sergeant Stu Fleming confirmed the two Splash Planet staffers had spoken to customers before midday and the "matter has deteriorated from there".
Mr Fleming said CIB detectives were investigating the incident today.
The council's chief executive, Ross McLeod, said violence of any nature at Splash Planet was unacceptable.
The water theme park opened for the 2008/09 summer season last Monday.
"We have never had anything like this happen at Splash Planet and we are shocked at the level of violence in this incident," Mr McLeod said.
"Staff are trained on how to handle difficult situations and in how not to let them escalate."
Mr McLeod said trespass notices would be issued to anyone involved and management would examine procedures and staffing mix to minimise risk for staff.
He said the injured staffers were released from hospital on Sunday night but both would require further treatment for their injuries.
Police have appealed for witnesses to the assault. Information can be given on 873 055 or the Crime Line 0800 567 789.
