Around 5.45pm on Monday 2 December a man was allegedly assaulted at his residence by a group of people.
Two people were arrested on Friday 6 December and appeared at Hastings District Court on Monday 9 December.
Another three people were arrested on Monday 9 December and are due to appear at Hastings District Court on Friday 13 December.
The latest arrests are in addition to 13 arrests made on Thursday 5 December.
Those arrested are believed to be Mongrel Mob Redcoats members or associates.
All 18 have been charged with Participating in an Organised Criminal Group and more charges are likely.