An aftershock measuring 5.5 on the Richter scale hit west China at 1:38 AM on Friday, the National Seismograph Network Center said.

The quake struck an area at 32.9 degrees north latitude and 105.6 degrees east longitude. The depth of the epicenter is about 6km.

The area joins Qingchuan County of Guangyuan City in southwestern Sichuan Province, Wudu District of Longnan City of northwestern Gansu Province, and Ningqiang County of Hanzhong City of northwestern Shaanxi Province.

No casualties have been reported.

(Xinhua News Agency September 12, 2008)