AlQa'dah 11, 1432, Oct 9, 2011, SPA - A magnitude-5.5 earthquake rocked New Zealand's quake-ravaged second largest city Christchurch Sunday following a series of tremors the previous day. Seismologists at the state GNS Science said the quake at 8.34 pm (0734 GMT) was centered 12 kilometres below the surface about 20 kilometres east of the city. There were no immediate reports of injury or damage, according to a report of the German Press Agency "DPA".