Barely recovering from the devastating earthquakes in February Christchurch City in New Zealand has again encountered consecutive earthquakes today measuring magnitude 6 and 5.5.

The magnitude 5.5 quake struck at 1pm local time (11am AEST), 10 kilometres east of Christchurch at Taylor's Mistake beach, at a depth of 11 kilometres, and sent people scrambling for cover reports from the stuff.co.nz said.

The magnitude 6 quake followed at 2.20pm and was centred 10 kilometres south-east of the city, it added.

Mayor Bob Parker told Radio NZ the second large quake was bigger than the 1pm one.

"Thank God we had evacuated the red zone. We are being enveloped with dust. It is very very scary. We need to get a picture of what is really happening and to make a call on where we need to send our essential services."

Some debris were reportedly have fallen from the ChristChurch Catheral in the second aftershock, sending up large clouds of dust.

There are also reports that another building in Lichfield Street has fallen down.

The Sydney Morning Herald said in a report that six people were taken to Christchurch Hospital with moderately serious injuries due to falling building material after the 1pm earthquake. St John Ambulance said several ambulances were operating in the city and some on standby.

Buildings were damaged, power was knocked out and new liquefaction has emerged. (More reports to be posted)