Mongrel Mob member Kevin Ratana, 27, has been named as the victim of the shooting in Whanganui on Tuesday morning.
There were reports of a series of gunshots at around 9am on Puriri St in the suburb of Castlecliff, and police confirmed later in the day that a man had died.
Police are hunting for those responsible, and speaking to residents in the area.
"The investigation is ongoing but we would like to remind the public that the victim and offenders were known to one another and police, so there is no cause for alarm," Detective Inspector Ross McKay said.
There has been an unofficial truce between warring gangs, according to residents in the area, and they fear that this incident could spark tensions between them again.
Cordons are likely to remain in place on Puriri St until later on Wednesday or Thursday, and there is a large police presence in the city.
Deputy Mayor Jenny Duncan says residents shouldn't be alarmed.
"We have that strong police presence here in Whanganui, which is of course very reassuring for our usually very quiet community," she told RadioLIVE.
"We're just waiting for the police to complete their investigation and apprehend those responsible."
Anyone who witnessed anything suspicious can call Whanganui Police on (06) 349 0600, or contact Crimestoppers anonymously on 0800 555 111.