Nine motorists have been processed for drink driving after a targeted Canterbury police operation in Rangiora and Kaiapoi.
More than 800 breath screening tests were carried out in and around the towns over the weekend, Senior Sergeant Stephen McDaniel said.
Three of the drivers who failed a breath screening test had come directly from a local bar, McDaniel said.
"Police are currently looking into this matter further. This behaviour is disappointing.
"Driving under the influence of alcohol puts everyone at risk - not just the driver, but passengers, other road users and pedestrians.
"Police remind the public that you can be stopped anywhere, at any time.
"Alcohol checkpoints are a regular part of our prevention strategy, and impaired drivers will be held accountable," McDaniel said.