The death toll from Tuesday's strong aftershock in southwest China's Sichuan Province had risen to three, local disaster relief headquarters said on Wednesday.
The aftershock, measuring magnitude 6.1, hit Yaodu Township of Qingchuan County, in Guangyuan City, at 5:49 p.m. on Tuesday, causing two deaths and 29 injuries, the provincial disaster relief headquarters announced on Wednesday.
Nine severely injured people were being treated in the city's downtown hospitals.
It destroyed more than 2,700 houses in Qingchuan and damaged 597 houses in Chaotian and Yuanba districts.
Water and power supplies were cut off in the town. Communication facilities were also damaged, which hampered the rescue efforts.
Another magnitude 4.5 aftershock hit Qingchuan at 7:55 a.m. on Wednesday, said a source of the Sichuan Provincial Earthquake Bureau. But no report of casualties and damage was immediately available.
More than 300 people, including local police personnel, have participated in the rescue operation.
In neighboring Gansu Province, the tremor left one person dead and six seriously injured in Wenxian County of Longnan City, said a provincial civil affairs department official on Wednesday.
The disaster also damaged highways and bridges in the city. Traffic on National Highway No.212 was disrupted after a bridge on the road collapsed as a result of Tuesday's quake.
Both Qingchuan and Longnan were severely hit by the May 12 magnitude 8 earthquake, centered on Wenchuan County in Sichuan.
The China Earthquake Networks Center said Tuesday's aftershock emanated from about 10 km underground. The tremor was felt in the cities of Hanzhong and Xi'an, both in Shaanxi, as well as Chongqing, prompting many people to flee their buildings.