Two people have died in an overnight crash just north of Christchurch.

Emergency teams rushed to the crash on Butchers Rd, Clarkville, at about 12.10am today.

They found two people dead at the scene, while a third was taken to hospital with minor injuries, police said.

Butchers Rd is expected to remain closed between Moodys Rd and Christmas Rd for much of the day, while repairs to a power pole take place.

Emergency teams are also currently responding to a serious crash in the North Island near Whanganui.

That crash happened on State Highway 3, near Blueskin Rd, Westmere, at around 10.15am, police said.

The Serious Crash Unit has been told about the incident, while SH3 remains blocked with diversions in place at Blueskin Rd and Western Line.

Motorists are advised to take an alternate route, police said.