Multiple deaths were reported as a 6.3 magnitude earthquake struck Christchurch in New Zealand Tuesday, toppling buildings, igniting fires and sending panicked people rushing into the streets.

People are evacuated from a damaged building after an earthquake in Christchurch, New Zealand, in this Feb. 22, 2011 image taken from video footage.

The widespread damage came from a shallow lunch-time tremor in a city of 340,000 still recovering from a powerful quake in September, which did not cause any fatalities but did weaken many buildings.

Christchurch airport was temporarily closed and police said they were evacuating the city centre as building frontages collapsed, with witnesses saying there were people trapped inside.

Cars were buried under rubble and roads buckled as the tremor opened ruptures in the ground.

"It was just unbelievable, it was so strong, nothing like I\'ve ever experienced before, just horrible," local shopkeeper Julian Hogday told TV3.

Police feared multiple deaths, including in two buses that were crushed by falling debris.

"Multiple fatalities have been reported at several locations in the central city, including two buses crushed by falling buildings. A doctor and emergency services are attending," a police statement said.

"Other reports include multiple building collapses, fires in buildings in the central (city) and persons reported trapped in buildings."

New Zealand Prime Minister John Key feared the worst after the quake struck at 12:51 pm (2351 GMT Monday), five kilometres (three miles) from the city at a depth of just four kilometres.

"It is a very populated time with people at work, children at school," he said.

"Sadly I cannot rule out whether there have been fatalities or not, but we are aware of significant damage to buildings that had people in them at the time."

On September 4, Christchurch suffered the most destructive quake to hit New Zealand in 80 years when a 7.0-magnitude tremor damaged 100,000 homes, leaving a clean-up bill estimated at NZ$4.0 billion dollars (US$3.0 billion).

The city remained under a state of emergency for weeks with police cordoning off the centre for fear of collapsing buildings, as thousands of aftershocks hit the region.

At the time, authorities gave a clean bill of health to Christchurch\'s 36,000-capacity AMI stadium, one of the venues for the rugby World Cup starting in September.