A 3.4 magnitude earthquake has been detected 10km west of Masterton.
GeoNet reported the earthquake hit just after 6.45pm with a depth of 25km.
Its intensity was classified as light but likely felt.
The quake follows a strong magnitude 5.2 quake in the same area early this morning.
This morning's quake, which was located 15km west of Masterton and struck at a depth of 24km, disrupted commuter train services out of the Wairarapa and prompted checks on the region's bridges.