The magnitude 5.5 quake struck at 1pm, 10 kilometres east of Christchurch at Taylor's Mistake beach, at a depth of 11 kilometres, and sent people scrambling for cover. It was followed at 2.20pm by a more powerful magnitude 6 quake, centred 10 kilometres southeast of the city and 9km underground.
At least 40 people were injured in the earthquakes today, including two who were injured seriously, Radio New Zealand reported. At least ten people were taken to Christchurch Hospital with injuries due to falling building material after the 1pm quake.
Other residents from the devastated city cried in the streets and hugged their children.
Police said there had been no deaths.
Lines company Orion said 20,000 homes and businesses in eastern Christchurch were without power at 7pm. It was unlikely power would be restored to them overnight.
The company said crews were making good progress in restoring electricity to the city. The earthquakes had initially knocked out power to 56,000 homes and business.
