A state of emergency was declared following Saturday morning's magnitude-7.1 earthquake in Christchurch, New Zealand.

New Zealand Civil Defense Minister John Carter rushed to Wellington, where the National Crisis Management Center in the Beehive has been activated to monitor the quake and coordinate central government response.

He announced a state of emergency had been declared about 10 a. m. Saturday, to give Civil Defense officials more power.

Carter, Prime Minister John Key and Energy Minister Gerry Brownlee would fly to Christchurch aboard an air force plane on Saturday afternoon.

The earthquake struck about 40 km west of Christchurch at 4:35 a.m. on Saturday (1635 GMT Friday), at a depth of 10 km, causing injuries, structural damage and gas leaks, cutting off power, and rupturing water and sewerage mains.

The New Zealand Institute of Geological and Nuclear Science ( GNS Science) earlier put the magnitude at 7.4.

At least two men were seriously injured in the massive earthquake which mainly affected New Zealand's South Island.

The two were injured by falling masonry and glass, local media reported.

One of them, in his fifties, was in serious condition in hospital after being hit by a falling chimney. The other was cut by glass.

The local hospital has also treated a number of people with broken bones, and others with minor injuries such as cuts and bruises.

Search and rescue teams have been deployed around Christchurch to check for trapped people in the rubble of the major earthquake.

Christchurch fire service spokesman Mike Bowden said there were a number of people trapped in their houses and other buildings by falling chimneys, jammed doors and blocked entrances.

The central business district of Christchurch has been closed to all traffic as police try to keep sightseers and looters from the scene.

Civil Defense has activated its emergency management centers throughout South Island's Canterbury region in the wake of the massive earthquake.

Carter urged the public in Christurch not to panic, and said plans were in place to get milk tankers full of water into the city. But he admitted that the water was likely to be rationed and people must conserve it, as it was likely to be several days before normal water supply was restored.

The army had been informed and was ready to mobilize if needed, and all systems were operating as they should in an emergency, Carter said.

Helena Wang, a resident in Christurch, told Xinhua that the quake was strongly felt in the city. It rocked her house violently, causing books on the shelf to fall to the ground. She added that electricity was out in her house and there were also aftershocks.

Some residents were out in the streets in their pajamas, looking scared and worried.

A spokesperson with the lines company Orion said power is out in most of Christchurch because of the extensive damage there. The spokesperson added that sewer lines and water pipes have ruptured, and whole substations are offline.