The Chinese Earthquake Bureau on Wednesday reported that a quake measuring 6.1 in magnitude had shaken part of Sichuan province, with a second quake measuring 4.5 in magnitude following minutes later.
Chinese state media reported that at least four people had died and 14 others were injured in the quakes.
The quake's epicenter was near Ya'an city, about 110 kilometers (65 miles) southwest of the provincial capital of Chengdu. It struck at a depth of 17 kilometers, at about 5 p.m. local time, and tremors were felt in cities across Sichuan province.
Authorities in the city said they had sent some 4,500 rescue workers to the site amid reports that the earthquake had triggered a landslide that damaged homes and a cement factory.
Local authorities said they were "going all out to rescue those who have been trapped... and reduce the number of dead to the greatest extent possible."
Provincial authorities said on Wednesday that there were no reports yet of buildings collapsing.
The US Geological Survey registered a lower magnitude of 5.9 for the first quake and said it was more shallow, at a depth of 10 kilometers.
The mountainous province is a popular tourist destination, being touted as the home of China's giant pandas. It is also highly prone to earthquakes.
A shallow quake between Sichuan and neighboring Yunnan in January this year injured more than 30 people. Another, in September last year, caused three deaths.
The province saw some 90,000 lives lost and widespread devastation when a magnitude 8.0 earthquake hit Wenchuan county in 2008 — China's deadliest earthquake in recent history.
rc/sms (dpa, AFP, AP)