Southern district road policing Inspector Craig Brown, of Dunedin, said the signs appeared to have been knocked over by a vehicle, some for a second time after being repaired.
"They may think it’s funny, but it’s not. It’s just plain dangerous."
He said people could be killed or seriously injured at some of the North Taieri intersections where signs had been removed.
They were dangerous enough with the road signs up, let alone someone knocking them down and making the intersections almost invisible to drivers.
"It poses a significant risk of crash and serious injury, especially when we’re talking about Stop signs, Give Way signs, speed limit advisory signs for people approaching intersections and bends, when those signs aren’t visible.
"If you’re looking at the School Rd and Gordon Rd intersection and a couple of those other intersections like that out there, you definitely need those road signs and markings to be present.
"People have been killed at some of these intersections."
"Those signs are there for a reason, and the danger that is being created by this mindless behaviour is one issue.
"The other is the cost of reinstating them."
He believed it might be the work of a young person or people in a four-wheel-drive vehicle.
"We’re seeing this vandalism across the Taieri, including Outram Glen and other reserves, where young people in four-wheel-drive vehicles are making a real nuisance of themselves and causing a lot of damage."
He urged anyone who witnessed the behaviour to photograph it and forward it to police.
Insp Brown said police were making "active inquiries".
In the meantime, they advised drivers to be extra vigilant and report missing road signs immediately.
