A curfew in the central business district of New Zealand South Island's largest city of Christchurch, following Saturday's massive quake, was lifted at 7 a.m. on September 5, 2010.

However, cordons were still in place in some streets where crumbling buildings are off-limits. Police are manning checkpoints around the city's center, and only residents and hotel guests are being allowed through.

The cordons are in place to protect the public from falling rubble and to prevent looting, police say. Engineers are now assessing the stability of many of the inner city's buildings.

Several people were arrested on Sunday morning after trying to get inside the area. About 80 policemen from Auckland flew to Christchurch on Saturday to help maintain order.

Christchurch was still under a state of emergency following the magnitude 7.1 earthquake at 4:35 a.m. on Saturday.

Civil Defense estimates that more than 500 buildings sustained damage. An assessment will begin on Sunday.

Central Christchurch streets are piled with rubble. Buildings and infrastructure were damaged throughout the city and region.

The Christchurch City Council said in a statement that of the 500 damaged buildings, more than 90 were in the central city area.

While there had been damage to minor bridges, major ones had withstood the quake. However, some roads had been closed due to liquefaction or flooding.

More than 240 residents left their damaged homes, taking shelter at three welfare centers set up in the city on Saturday. The centers would remain open as long as they were needed.

Civil Defence said people forced out of their homes because of quake damage, should be prepared for the emergency to continue into next week at least.

Christchurch was still being shaken by aftershocks. Since 8 p.m. Saturday, 17 aftershocks have been reported by the Geonet website, including three between 5 a.m. - 6 a.m. Sunday. The largest at 5: 20 a.m. was 5.1 on the Richter scale.

All are centered south of Darfield, the same area as the center of Saturday's magnitude 7.1 earthquake.

On Sunday, the residents will be hyper-alert for more, though the risk of large shocks falls away sharply after 48 hours.

Strong winds are forecast for Christchurch and the Canterbury region on Sunday. Civil Defence was worried that already unstable buildings may be affected.

Christchurch Mayor Bob Parker is worried that forecast bad weather, including gale force winds, will make the earthquake damage worse.

About 20 percent of Christchurch was without power Saturday night and a third was without water. On Saturday morning following the massive quake, there was a period of panic. People rushed to the supermarkets to buy drinking water, food and batteries. Supermarkets have sold out water. Patches of central Christchurch were gridlocked as residents rushed to fill up with petrol.

Then the panic passed. There was an astonishing atmosphere of resilience and even relief, as a community rallied and shared its bottled water with neighbors.

Two men in their 50s were the only reported serious injuries caused by the massive earthquake. One man, hit by a collapsing chimney, was in a critical condition in hospital, while another was being treated for deep cuts.

Another Christchurch resident died of a heart attack as the quake struck. Doctors could not confirm whether the death was linked to the earthquake.