People inspect a crack caused Saturday in the South Brighton Bridge approach in Christchurch, New Zealand. A powerful 7.1-magnitude earthquake struck much of New Zealand’s South Island early Saturday and caused widespread damage, but there were just two reports of serious injuries.

Wellington, New Zealand ? A powerful 7.1-magnitude earthquake damaged buildings, cut power and knocked fleeing residents off their feet on New Zealand’s South Island early today, but there were so far no deaths and only two injuries reported.

Panicked residents in their pajamas ran into the streets of the southern city of Christchurch after the pre-dawn quake, residents said. There were reports of some people trapped in damaged buildings — though none appeared to be crushed by rubble — and a few looters broke into some of the damaged shops in the city of 400,000, authorities said.

Chimneys and walls had fallen from older buildings, roads had been blocked, traffic lights out and power, gas and water supplies disrupted, Christchurch Mayor Bob Parker said. He warned that continuing aftershocks could cause masonry to fall from damaged buildings.

“The fronts of at least five buildings in the central city have collapsed, and rubble is strewn across many roads,” Christchurch resident Angela Morgan told The Associated Press. “There is quite significant damage, really, with reports that some people were trapped in damaged houses.”

Suburban dweller Mark O’Connell said his house was full of smashed glass, food tossed from shelves, with sets of drawers, TVs and computers tipped over.

“We were thrown from wall to wall as we tried to escape down the stairs to get to safety,” he told the AP.

The quake, which hit 19 miles west of Christchurch according to the state geological agency GNS Science, shook a wide area, with some residents saying buildings had collapsed and power was severed. No tsunami alert was issued.

GNS Science initially reported the quake as magnitude 7.4, but later downgraded it after re-examining quake records. The U.S. Geological Survey, in America, measured the quake at 7.0.

Army troops were on standby to assist, Minister of Civil Defense John Carter said, as a state of civil emergency was declared.

“I think we’ve been extremely lucky as a nation that there’s been no fatalities,” Carter told reporters, though he said infrastructure damage was major. Earthquake and insurance specialists would give government an initial damage assessment within 48 hours, he said.

Parker said the quake caused “a lot of damage to our key infrastructure … water, waste water (sewerage) systems … but the most important thing is that there has been no loss of life.”

Christchurch fire service spokesman Mike Bowden said a number of people had been trapped in buildings by fallen chimneys and blocked entrances, but there were no reports of people pinned under rubble. Rescue teams were out checking premises.

Christchurch Hospital said it had treated two men with serious injuries and a number of people with minor injuries.

One man was hit by a falling chimney and was in serious condition in intensive care, while a second was badly cut by glass, hospital spokeswoman Michele Hider said.

Christchurch police reported road damage in parts of the city of 400,000 people, with a series of sharp aftershocks rocking the area. Police officers cordoned off some streets where rubble was strewn about. Video showed parked cars crushed by heaps of fallen bricks, and buckled roads.