Christchurch CBD (file)

Christchurch was struck by its biggest aftershock in months last night, after a weekend of jolts.

The 4.8 magnitude quake occurred just after 5pm last night at a depth of 8km.

It struck 20km east of the city.

Earlier in the day, at 9:35am a 4.1 magnitude quake hit near Rolleston.

According to Geonet duty seismologist Caroline Little there was a total of 17 aftershocks, though police say there are no reports of damage.