BEIJING, July 3-- The 6.5-magnitude quake in northwest China's Xinjiang Uygur Autonomous Region is not likely to trigger a heavy deathtoll, Director of the China Earthquake Networks Center (CENC) Pan Huaiwen estimated based on the local population density.

He said the population density in a 50-square-kilometer scope of the epicenter is four persons per square kilometer, a relatively low density.

Four people have been confirmed dead and 48 others injured in the quake

that rocked Pishan County of Hotan Prefecture at 9:07 a.m. Friday. The epicenter is 7.5 km from the county seat.

As time goes by, deathtoll and injuries might rise, Pan said.

Shortly after the quake, the area was hit by smaller tremors measuring between 3.0 and 4.6 magnitude.

Jiang Haikun, director of the CENC's forecasting department, said the quake is not likely to trigger an aftershock with a magnitude higher than 6.5, but aftershocks around magnitude 5 are likely.

Jiang said, the quake was a result of the pile-up and release of stress in this region, not triggered by the Nepal earthquake in April.

Located in southernmost Xinjiang, Pishan is about 1,800 km from the regional capital of Urumqi and covers 39,700 square km.

With a population of 258,000, the county is mainly inhabited by people of Uygur ethnicity.