Two earthquakes struck the South Island late last night.

A magnitude 5 strong quake hit 35km north-east of Hanmer Springs just before 11.30pm. It was measured at a depth of 28km.

A 4.6 magnitude aftershock struck shortly afterwards.

Earlier last night, just after 8.30pm, A 3.8 magnitude quake struck north of Wellington at a depth of 57km.