Quake struck south of Wairoa yesterday evening.

Earthquakes struck about 20km south of Wairoa yesterday evening.

GeoNet said there had been a series of eight earthquakes during the day, the largest of which was a magnitude 4.2 at 5.46pm. It was reportedly felt in Napier, Hastings and Wairoa.

Six of the shakes hit within an hour, between 5.30pm and 6.30pm yesterday.

However, GeoNet duty seismologist Caroline Little said the flurry of activity was not unusual and they were unlikely to have caused damage.

The quakes struck on what was the second anniversary of the 2011 Canterbury earthquake, in which 185 people lost their lives.

The first of the series yesterday evening was a magnitude 3.1 and was 18km deep and 30km south of Wairoa.

Five more shakes followed over the next hour, the latest registering at 6.15pm, 20km south of Wairoa.

"There's been about a dozen 'felt' reports for the largest one, the 4.2," Ms Little said. "They were mostly around Napier, Hastings and there were two in Wairoa.

They were unlikely to have caused damage.

"The intensity is [classed as] light intensity, so they would have just noticed there was an earthquake and nothing much else."

It was not unusual for such activity, she said.

"It's not unusual, but it doesn't happen every day, obviously.

"In the last month we've had 183 earthquakes in Hawke's Bay so to have eight around Wairoa isn't uncommon."

Wairoa Mayor Les Probert and several other Wairoa District Council members contacted last night all said they hadn't felt the shakes.