A state news agency says a strong aftershock has rattled cities throughout China's earthquake zone. The U.S. Geological Survey measured the temblor Monday afternoon at magnitude 5. Xinhua News Agency said the aftershock shook the Sichuan provincial capital of Chengdu and the hard-hit city of Mianyang for about 10 seconds. It was not known whether the aftershock affected the brimming Tangjiashan lake, which was threatening more than 1 million people living downstream.
