The RSA is urging whoever vandalised a Battle of the Somme memorial in Wellington to own up.

The Victory Medal installation in the Botanic Gardens was damaged following a party on Friday night.

Rubbish and broken glass was also scattered across the Ridge of Remembrance.

RSA National President BJ Clark said people need to take responsibility for this silly act.

"I just think if there's anyone out there that knows who did this, or perhaps they might even be under the influence, even though that's not an excuse, they might like to come forward and cleanse their soul."

Mr Clark said it's incredibly disappointing.

"I've got no time for vandalism and that's a real pity when the botanic gardens are such a special place in Wellington and a memorial like that in particular. It's always disappointing when people don't treat things with respect.

"To go and do the damage is mindless and gutless. In fact, if anyone thought it was any other, then they could quite happily give me a ring and I'm quite prepared to discuss the issue with them."

Mr Clark said thankfully these incidents aren't common, but one is too many.

"These are memorials to remind us of the sacrifice and the commitments given, and I think it's very sad if we can't allow those memorials to sit there."

Lambton Ward Councillor Nicola Young said it's just plain vandalism.

"It will be a pity if we have to follow the European example and have to have CCTV cameras everywhere - that would be a real shame."

"But if people are going to behave like this we have to work out how we're going to deter them."

Security guards will now patrol the gardens.