In New Zealand, an overnight curfew has been imposed in Christchurch, the second largest city, which was hit by a powerful 7.0-magnitude earthquake early this morning. Police said the curfew was intended to protect people from falling debris, as the quake caused significant damage. Many homes have suffered damage in the quake. Water, power and sewerage are also affected and the airport is closed. Two men were seriously injured by falling masonry and glass, but there have been no reports of fatalities.The mayor of the city, Bob Parker, described the scale of the damage as immense, and a state of emergency has been declared. There have been strong aftershocks, and weather forecasters say gale force winds are expected within 24 hours. The quake caused considerable infrastructure damage, but local officials say power has been largely restored and tankers will supply water. The Prime Minister John Key along with Civil Defence Minister Jonh Carter visited the quake-hit city to assses the damage. According to US Geological Survey, the quake struck off the country's South Island in the early hours this morning when most people were asleep. The epicentre was 44 kilometres west of Christchurch at a depth of about 5 kilometres.The country experiences more than 14,000 earthquakes a year, of which only around 20 have a magnitude in excess of 5.0. The last fatal earthquake was in 1968, when a 7.1-magnitude tremor killed three people on the South Island's western coast.