A swarm of earthquakes rattled the Gisborne coast overnight.

The first came soon after 1am, measuring 4.2 on the Richter scale and centred 50km east of Tolaga Bay.

Just a few minutes later it was followed by a magnitude 3.8 tremor, at a depth of 21km.

At about 1.50am there was another measuring 3.4, and five minutes later the earth shook again at a depth of 20km.