The earthquake that killed one person in southwest China's Sichuan Province Sunday was not an aftershock of the 8-magnitude quake of May 12, 2008, said Lu Yipei, deputy director of Sichuan Provincial Seismological Bureau, Monday.

Experts were still investigating the cause of the 5-magnitude quake, he said.

"We are sure this quake is not an aftershock because of change in geological structure and environment caused by the devastating quake in May 2008, which left about 87,000 people dead or missing," Lu said.

The earthquake, which struck the juncture of Sichuan's Suining City and Tongnan County of Chongqing Municipality at 5:36 a.m. Sunday, also injured 15 people and caused more than 2,000 to be relocated as of Sunday.

Experts said the possibility of aftershocks could not be ruled out, but no after shock had been reported within 30 hours after the quake, according to the Sichuan provincial earthquake authority.

The quake brought an economic loss of over 367 million yuan (about 54 million U.S. dollars) to Suining city, said Wang Song, a local government official.

As of 6 p.m. Sunday, the electricity supply had been resumed for 790 households and reached the 45 tents and five temporary residence areas, said Zhang Jianting, deputy manager of Sichuan Provincial Electric Power Corporation under the State Grid Corporation of China.

Sichuan Red Cross Society had allocated more than 640,000 yuan worth of relief supplies, including medicine, tents and daily necessities, to the quake-hit area.

More than 1,200 soldiers and militiamen had been dispatched to the quake area to evacuate the residents, set up temporary residences and provide medical service.

Each person in the temporary residences would receive 360 yuan in subsidy a month, said an official of the Suining municipal civil affairs bureau.