More than 1,000 people were injured in the magnitude 6.0 aftershock, according to state media. The China National Seismic Network reported it was the strongest of dozens of aftershocks since the first 7.9-magnitude earthquake, which was the deadliest quake in the province in 32 years.
The latest confirmed death toll from the disaster is 65,080, with nearly 24,000 people still missing. China's Premier Wen Jiabao has warned the causalities could reach 80,000.
Chinese officials are concerned that 70 dams in the central region of the country are on the brink of bursting after sustaining more damage from the aftershock.
Massive landslides and falling debris clogged a river and created a swiftly rising lake that could cause flooding southwest of Sichuan. Nearly 2,000 police officers and soldiers were sent to the site Monday with dynamite to break down some of the barriers and control the water flow, reported CNN.
The fresh destruction added to the millions of people already forced to live in makeshift camps, and renewed fears that conditions will worsen.
"Houses started to shake and everybody went out into the street," Lou Taiyi, a Chengdu resident who experienced the aftershock told AFP.
"We were thinking (May 12) was behind us but it is continuing."
International aid efforts in the region have been praised by the Chinese government, and Premier Wen Jiabao thanked the international community for its help during a Saturday visit to an affected area with UN Secretary General Ban Ki-moon.
After Sunday's quake Russian planes brought tents, blankets, field hospitals and other supplies to Chengdu, and a French medical team went to Guangyuan to help treat quake victims.
The Chinese government has asked a factory creating prefabricated housing to work overtime and is preparing a site In Dujiangyan, near Chengdu, for prefabricated housing for 1,000 people.
The white buildings with metal roofs will provide 86 square feet of housing for one family.
"The most important thing is getting people into temporary housing and stabilizing the health and hygiene situation," Zhang Haibo, a health inspector from Shandong province in eastern China, told CBS.
