In a 24-hour period ending at noon Thursday, the China Earthquake Administration said it monitored 166 aftershocks in southwest China's quake zone, reported Xinhua, China's official news agency.

Two measured from 4 to 4.9 on the Richter scale and the others registered at or below 3.9, the administration said.

An aftershock measuring 5 jolted Sichuan's Qingchuan County Thursday afternoon after the measurement period, the administration said.

A total of 373,612 people were injured and 17,918 others are still missing in the May 12 quake; 45.71 million people were affected by the event, Xinhua said.

Hospitals reported treating 97,631 people, of whom 74,165 have been released.

Meanwhile, more than 30,000 people in Sichuan province's mountainous regions reportedly are still without water, despite the massive earthquake relief effort in China.

However, Hou Xiongfei, a government spokesman in the worst-hit province, said the water supply has been restored to more than 5.7 million people since the May 12 disaster.