Two children were airlifted to Starship Hospital in critical condition after a multi-injury crash that shut down a section of State Highway 1 north of Wellsford on Monday evening.

Emergency services were called to the scene shortly after 4.30pm, where several people were found injured following the collision. Paramedics dispatched multiple ambulances, rapid-response units and a rescue helicopter as they worked to stabilise the patients.

Alongside the two critically injured children, one person was transported to Auckland City Hospital in a serious condition. Another patient with moderate injuries was taken to North Shore Hospital.

The crash forced the closure of SH1 between the SH16 junction and Davies Road for several hours while emergency crews worked and investigators examined the scene. Northbound motorists were diverted to SH16, while southbound drivers faced significant delays.

Police said the New Zealand Police Serious Crash Unit is carrying out a full investigation into the cause of the incident.