An earthquake with a magnitude of 5.6 Tuesday damaged thousands of houses in Sichuan province, where an 8.0 magnitude quake in May 2008 left nearly 90,000 people dead or missing and 5 million homeless.

The quake, which experts say was an aftershock of last year's catastrophe, occurred at 2:03 am in Mianzhu and destroyed 8,600 houses, 60 bridges and about 30 km of fiber-optic cables, according to the Xinhua News Agency.

Another aftershock, measuring about 5.0 magnitude, occurred at 3:24 pm Tuesday, the provincial earthquake administration reported.

"It was a strong tremor. I could hear sounds like trains running beneath my feet. I ran downstairs with some other locals," said Wei Xiao, a 22-year-old college graduate in Mianzhu, told China Daily.

Rendong, a Mianzhu blogger based at Sina.com, a popular portal, said in a blog entry at 2:22 am Tuesday that the earthquake "went on for about 10 seconds and felt like at least a 6.0 magnitude aftershock".

"It's so frightening that such a strong aftershock would occur more than a year after May 12 (of 2008)! It'd be certainly hard to sleep tonight I hope no one was injured," he said.

Eight quake-related injuries were officially announced, while an anonymous social worker in Mianzhu told China Daily the local civil affairs bureau "confirmed three deaths".

Li Juan, a staff member of the Deyang foreign affairs office, refuted the claim, saying she only heard of "some tiles falling off obsolete rural houses".

Members of the provincial emergency response office, who were sent to Mianzhu after the quakes, said little damage was found in the area.

Luo Yingguang, chief of publicity with the Mianzhu Committee of the Communist Party of China, said a road to Qingping collapsed in the earlier aftershock.

Power and telecommunications services were disrupted, and a water pipeline leak was reported, he said.

An unconfirmed number of local reservoirs and protective embankments, as well as some small bridges and culverts, sustained minor damage, Luo said.

The earlier tremor Tuesday was felt in Sichuan's provincial capital of Chengdu, the cities of Deyang, Mianyang and Guangyuan, as well as the Aba prefecture, the local earthquake administration said.

Mianzhu is about 40 km from Wenchuan, epicenter of the May 2008 quake, which caused 11,117 deaths and 37,000 injuries. About 92 percent of the houses were damaged by that tremor, according to official figures.

Some 57,000 aftershocks have been recorded in Sichuan since that earthquake, local seismologists said.