BEIJING POLICE SEEK PUBLIC'S HELP IN BOMBING.

Byline: Associated Press 

Police appealed for help from the public Saturday in investigating an explosion at a Beijing bus stop that injured at least eight people amid unease about a series of deadly bombings in China's remote northwest.

A brief announcement on Beijing's local television news said police wanted information from passengers on the bus, but did not say whether they had determined the cause of the blast Friday evening outside a shopping center.

However, a source told the Associated Press that public security officials said the explosion was caused by a bomb made of a water pipe stuffed with gunpowder and set off by a washing machine timer.

The officials made the disclosure at an emergency meeting with security chiefs of central Beijing public buildings, said the source, who spoke on condition of anonymity.

The explosion occurred 10 days after bombs exploded on three buses in the restive region of Xinjiang. Official media said those blasts, blamed on Muslim separatists, killed nine people.

Such attacks are almost unknown in the Chinese capital, where security - already tight because China's legislature is meeting - was stepped up after the Xinjiang bombings and the death of senior leader Deng Xiaoping on Feb. 19.

The unrest in Xinjiang has emphasized the challenges facing President Jiang Zemin.