国际英语新闻：More aftershocks occur overnight in New Zealand South Island's Canterbury region

WELLINGTON, Sept. 7 (Xinhua) -- More aftershocks have occurred in New Zealand central South Island's Canterbury region after a swarm of strong quakes overnight.

A magnitude-5.4 quake was recorded at 3:24 a.m. Tuesday. It was located some 20 km south of Darfield, at a depth of 15 km, the GNS Science reported.

Another magnitude-5.4 tremor was recorded at 11:40 p.m. on Monday, some 20 km southwest of Darfield and at a depth of 9 km.

These quakes are of the same magnitude as the most severe aftershock recorded at 4:55 p.m. Saturday.

A magnitude-5.2 quake was recorded at 11:24 p.m. Monday, 20 km southeast of Darfield, also at a depth of 9 km.

Civil Defense (CD) advises residents to prepare for even bigger aftershocks.

CD duty manager John Mitchell said he has been told by geologists that an even stronger quake could occur.

He said it is unlikely for the latest aftershocks to cause any new damage, but they could have further undermined the integrity of the buildings that are already damaged.

Christchurch is still under a state of emergency after a magnitude-7.1 earthquake hit the city at 4:35 a.m. Saturday.

A 7 p.m. to 7 a.m. curfew is also in effect. The Army is on duty on the streets of the central city.