The back-up batteries for the cell phone towers have run out of power, after the grid went down due to the severe tremors. 75 percent of the city remains without power.
Up to 250,000 people may be affected by the blackout, cutting off vital cell phone communication lines. Land lines remain active, according to local residents.
The Christchurch Hospital is running on generator power. At least two people suffered serious injuries, the public broadcaster said, citing Christchurch Hospital.
The epicenter was reported to be 35km from Christchurch at 4.35 a.m.
Eye witnesses have reported major damage, with buildings being “flattened”. Entire façades of building crumbled, crashing nearby cars.
Andy North, who lives just out of city, says the shock was beyond words.
“I woke up 30 seconds before it happened, something … I don’t know can’t put it into words … ,” he said over the phone.
“Buildings been flattened in the downtown area”.
“My room was basically total trashed, I live in a very very narrow room, my T.V. was literally damaged beyond repair, and my computer is broken … The earth really moved”.
“Everybody is heading to the dairy next door stocking up. In a very short space of time after the initial shock … there was a lot of sirens going off, a lot of activity like that … .”
Mr North says there has been looting reports near Christchurch. Some have reported sewage pipes bursting.
“I have another friend in another part of town, she has got no power, her property is flooded.”
The tremors were also felt as far as Lincoln, located 20km south-west of Christchurch.
“There is a very strong smell of sulfur in the area, its continuous,” said June Martin, a resident from Lincoln, over the phone.
“There are continuous aftershocks,” she added.
With reporting by Nicholas McLaughlin.