GeoNet said the quake - initially measured as magnitude 4.3 but an hour later upgraded to 4.4 - and a magnitude 3.6 foreshock caused moderate shaking in Christchurch this morning.
There had also been an earlier jolt yesterday evening and a magnitude 4 quake at the same spot overnight at 2.21am.
The most recent quake is the strongest of the latest batch.
GeoNet said more than 7000 people had confirmed they felt the shaking, with the majority measuring the jolt as light-to-moderate.
The quake was likely to have been felt across the Canterbury region as far as Arthur’s Pass and Hanmer Springs, said GeoNet.
Canterbury residents report feeling it as far north as northern Kaiapoi and far south as Ashburton, where one resident reported feeling an extreme shake.
Those living in the eastern Christchurch suburb of Woolston reported feeling the twin earthquakes more intensely than other parts of the city.
“That second one this morning definitely felt stronger than that here in Woolston,” said Sarah-Lee Larmer on GeoNet’s Facebook page.
“I’m in Woolston too. Seems like everyone in that area felt it a lot worse than in other parts of the city,” said Shem Brokenshire.
Other residents reported being woken up by the double quakes and hoping this would be the end of the cluster.
“Enough already...stop!” posted Syliva Oliver.
