They were due to appear in court tomorrow - two in Gisborne District Court and one in Hastings District Court.
The fourth man, aged 23, was arrested on Tuesday night for possession of offensive weapons.
Wairoa CIB Sergeant James Keene said the incident and a number of events prior have been linked to gangs.
"Gangs carrying out such violent acts in our town will not be tolerated," he said.
"The community deserves to be safe and feel safe at all times."
During the searches, police located and seized a shotgun.
Contact Wairoa Police on (06) 838 8345 or anonymously call Crimestoppers on 0800 555 111 if you have any information about the incident.