A deadly crash in Hauraki over the weekend is yet another horrific event of a kind that's becoming all too frequent on that stretch of State Highway 2, the district's mayor says.

Photo: RNZ / Claire Eastham-Farrelly

Police were still working to identify the four people who died in the fiery two-car crash at Netherton, north of Paeroa, bringing to eight the number killed on the country's roads this weekend.

Hauraki Mayor John Tregidga said the crash happened on a relatively straight section of the road, and heavy fog might have been a factor.

Mr Tregidga said a high accident rate had already prompted authorities to lower the speed limit on part of the highway north towards Auckland, but Netherton was missed off the list of sites for safety improvements.

However, he said his focus now was on those affected by the latest crash.

"It's just tragic that four people have lost their lives. We're just getting too many accidents...you've just got to feel for the family and the extended families. It's just horrific."

Police said one of two men injured in the crash was in a critical condition in hospital and the other was in a serious condition.

"We do know that there was heavy fog in the area at the time of the incident, but while the investigation is ongoing, we will not be speculating on the cause of the crash or whether this was a factor," said Inspector Marcus Lynam, in a statement.