Seven people - including two pedestrians hit by a train - have died in separate incidents around the country since yesterday afternoon.

Two people died after being hit by a train in Papakura, South Auckland just after 11pm last night.

A southbound train, travelling from Papakura to Pukekohe, hit the victims at the railway crossing with Boundary Rd.

Police said both people died as a result of the impact.

Just before midnight, two more people were killed after the car they were travelling in hit a tree in Kumeu, west Auckland.

The single car incident happened on Access Rd.

The Serious Crash Unit was examining the scene.

A female died after three cars collided just north of Towai in Northland on Friday afternoon.

The three-car crash happened on State Highway 1.

Two separate crashes in the South Island left two people dead and a number injured.

One person was killed and another was fighting for their life after a crash on State Highway 65 at Maruia in the Buller District.

A police spokeswoman said two vehicles were involved in the incident, near Memorial Lane, which happened at 9.10pm.

Four others were left with moderate to serious injuries, a police spokeswoman said.

The critically injured person was flown to Christchurch Hospital and the other four were also taken to hospital.

The Serious Crash Unit was investigating and police were working to inform next of kin.

One person also died following a serious crash on Waimate Highway (State Highway 1) in South Canterbury, involving three vehicles.

Four people were also injured, two moderately and two seriously, in the accident which happened in Morven just after 4pm yesterday.

One of the seriously injured occupants was airlifted to Dunedin Hospital and the other three were taken to Timaru Hospital.

State Highway 1 was closed for several hours while the Serious Crash Unit investigated.

Meanwhile, another crash on the Kapiti Coast left one person in critical condition.

The single vehicle crash on State Highway 1 in Te Horo happened around 10.10pm yesterday.

A child was also injured after a collision between a car and school bus in Queenstown yesterday afternoon.

A police spokesperson said they were called to the crash on Frankton Rd between Sugar Lane and Yewlett Crescent at 3.49pm.

A St John spokesperson said two patients were transported to Lakes District Hospital. One patient was a 8-year-old girl with minor injuries, and another patient sustained serious injuries.