A toxic gas leak from a chemical plant in east China has left five firemen ill and forced the evacuation of more than 2,000 residents. One of the five firemen was still in intensive care in a hospital after the incident in Hangzhou, the provincial capital of Zhejiang, a city government spokesman said today. At around 7 pm on Friday, thick fumes were detected at a warehouse for toxic materials at a chemical plant of the Hangzhou Hexiang Fine Chemical Co Ltd in Xiangfu town. Residents nearby began to smell a pungent odour, and their eyes watered and they complained of sore throats, he said. Soon, the fire brigade arrived and rescued 20 people from the factory area and evacuated 2,000 people, the official Xinhua news agency reported. Fire fighters used powder to stabilise the gas, and sprayed water to dilute it. In the early hours on Saturday, the situation was under control. The five firemen developed symptoms of vomiting and dizziness and they were taken to hospital immediately. The spokesperson said the toxic material was thiocarbamide. It emitted pungent gas in high temperatures. Environment tests and monitoring are underway, and the cause of the accident is being investigated.