Seven Chinese villagers died after being overcome by carbon monoxide while looking for agate stones in an abandoned mine, local authorities said Friday. The incident occurred Wednesday night in the small town of Beipiao in Northeast China's Liaoning province, the Xinhua news agency reported. The report, quoting the municipal information office, said an initial investigation determined six of the villagers had entered the mine without authorization and later died of carbon monoxide poisoning. The seventh victim, after failing to hear from his friends, went into the mine the next day and he too was overcome by the poisonous gas, the report said.