She said several vehicles were present and a person may have been hit by one of them. At least one vehicle has been impounded by police.
St John ambulance was called at 8.47pm, an ambulance spokeswoman said.
"We sent two vehicles and are currently transporting one patient in a serious condition to Tauranga Hospital," she said.
A resident who lives nearby told Bay of Plenty Times reporter Scott Yeoman he heard "a bunch of skids" happening down in Lyn Grove and then yelling started.
"Two guys came running through the back yard. And I just yelled out to them: Get the f*** off the property ... and one guy apologised and carried on running. Jumped the fence.
"Then another one, maybe a couple of minutes later, comes down and ... I'm like 'Dude, get the f*** off this property."
The resident, who did not want to be named, said the third man ignored him and was walking up and down and then jumped the fence "and buggered off as well".
Minutes later another three males walked past, he said.
"Two of them had what looked to be like fence palings. And one of them... he had a gun. I know a gun when I see one.
"But I couldn't tell you if it was just like a slug gun or whether it was a .22 or something like that."
He rang the police immediately. "Young family and everything, you ring the cops straight away."
It did not take long for the police to arrive, he said.
A Hartford Ave resident, who also asked not to be named, was out walking his dog when he heard a car doing a burnout.
"[I saw] a grey car that looked beat up and had a smashed back windscreen speeding past the park. Then I saw two groups of people running through the Hartford Ave park.
There were at least eight police cars on Hartford Ave and Lyn Grove, and Hartford was cordoned off at both ends for about an hour before the cordons were stood down at 9.40pm.
As of 11pm police were still at the scene working to establish exactly what had happened, a police spokeswoman said.