CHENGDU, China - One of the most powerful aftershocks to hit quake-ravaged central China killed one person, left dozens more injured and leveled homes Sunday, as soldiers carrying explosives hiked to a blocked-off river to alleviate the threat of floods.

Some 260 people were injured in the aftershock Sunday afternoon, the government-run China News Service said, with 24 in serious condition. The agency said many homes had collapsed and roads were damaged, but gave no specific figures.

The magnitude 5.8 aftershock was among the most powerful recorded since the initial May 12 quake, the U.S. Geological Survey said. The China National Seismic Network, which uses a different measurement system, said the aftershock was the strongest of dozens. The aftershock caused office towers to sway in Beijing, 800 miles away.

Earlier Sunday, the Cabinet said the confirmed death toll from the quake rose to 62,664, with another 23,775 people missing. Premier Wen Jiabao has said the number of dead could surpass 80,000.

Millions have been left homeless, and some are now at risk of being inundated by floods from new lakes created when landslides from the quake and aftershocks dammed rivers.

North of the epicenter, 1,600 soldiers and police were hiking to a blocked river outside Beichuan, each carrying 22 pounds of explosives to blast through the debris in hopes of preventing flooding, the official Xinhua News Agency reported. Bad weather meant they could not use helicopters to reach the lake.

The State Meteorological Bureau said parts of Sichuan would suffer heavy or even torrential rain later Sunday and Monday, warning of possible mudslides.

About 20,000 people have been evacuated from the disaster area due to the flood risk, and the total who need to be relocated could rise to 100,000, Liu Ning, chief engineer at the Ministry of Water Resources, told reporters in Beijing.

The ministry also said Sunday that 69 dams in Sichuan were in danger of collapse due to quake-related damage, among 320 dams at risk.

"If these reservoirs were to overflow, it would be a serious threat the lives and property of the people downstream, and will influence the supply of water for agriculture and industry," Vice Minister of Water Resources E Jingping said.

Authorities have said the world's largest water project - the Three Gorges dam, located about 350 miles east of the epicenter - was not damaged.

Meanwhile, state television reported Sunday that a survivor trapped by the initial quake was rescued alive Friday, more than 11 days after the disaster.

Xiao Zhihu, an 80-year-old bedridden man, was found in Mianzhu north of Chengdu after being trapped in his collapsed house, the report said. He survived because his wife was able to get food to him through the rubble, but there were no further details given or a reason for the two-day delay in reporting the rescue.

Some people paused Sunday to attend church almost two weeks after the quake hit. In Chengdu, worshippers gathered at the Ping'an Bridge Catholic church to say prayers for the victims.

A collection plate was passed around, and people gave everything from the equivalent of a few cents to 100 renminbi notes ($15).

One worshipper, 58-year-old retiree Liang Biqing, said the disaster had changed her views on China's place in the world and shown her that people globally all share the same troubles.

"This shows that there are no barriers, no nationalities, when it comes to disasters," she said.

Also Sunday, panda keepers at the Wolong Nature Reserve, a major breeding center for the endangered animals near the epicenter, said they had arranged for fresh bamboo to be trucked in for the pandas, center official Zhou Xiaoping told Xinhua.

Their home at the world-famous Wolong reserve was badly damaged in the quake. Five staff members were killed and two pandas are still unaccounted for.

Eight pandas from the reserve are spending the next six months at the Beijing Zoo on a special Olympics visit that was planned long before the quake. The animals were flown Saturday afternoon by special plane to Beijing from Chengdu.