The epicenter Kangding (red dot) is 325 km away from Chengdu, capital of Sichuan province. [Photo/CENT]

BEIJING -- China's Ministry of Civil Affairs (MCA) on Saturday said the quake in southwestern province of Sichuan are not likely to cause heavy casualties.

The MCA added that the quake might have caused collapses or serious damages of over 3,000 houses, and 20,000 houses moderately damaged.

A 6.3-magnitude earthquake struck Kangding County, Ganzi Tibetan Autonomous Prefecture of Sichuan Province, at 4:55 pm Saturday, the China Earthquake Networks Center said.

The epicenter was monitored at 30.3 degrees north latitude and 101.7 degrees east longitude. The quake hit at a depth of 18 kilometers, according to the center.

As of the press time, a woman in her 70s was killed at the scene after being hit in the head by falling debris in Ganzi. The quake was strongly felt in Kangding.

According to empirical model of the MCA, the quake's largest intensity is degree VIII in about 7 square kilometers. The degree V intensity of the quake struck an area of about 22,000 square kilometers, with 280,000 people being affected.

At the same time, the China Earthquake Administration has initiated the Class II emergency response mechanism.