In eastern Chinese city of Leqing, more than 3,000 residents have been evacuated after tonnes of ammonia, a pungent industrial gas, leaked out from a factory. Officials said ten people remain hospitalized nearly seven hours after the gas leak on Saturday. The factory boss said a valve was accidentally knocked off, causing the leak of about 1.4 tonnes of ammonia. Doctors say inhalation of large amount of ammonia can cause lung disease or even death in serious cases.