A series of powerful tremors rattled the quake-prone New Zealand city of Christchurch on Monday, destroying buildings and sending boulders tumbling down hillsides nearly four months after a quake killed 181 people in the city. There were no reported fatalities. New Zealand’s Civil Defence said 10 people suffered minor injuries in the quakes, with the strongest put at a magnitude of 6.0 at 2.20 p.m. (0220 GMT) local time. Buildings were evacuated and infrastructure damaged across the city, still trying to recover from the Feb. 22 6.3 magnitude earthquake. Monday’s quake knocked the New Zealand dollar lower and was seen as another hurdle to rebuilding New Zealand’s second largest city, likely encouraging the Reserve Bank of New Zealand to keep interest rates on hold for longer.