text: Nineteen people needed medical treatment and hundreds of firefighters deployed to fight a huge blaze at a Chinese chemical plant  that produces a toxic chemical. Authorities said initial tests suggested there had been no leaks from the plant's three tanks of burning hydrocarbon liquids and no signs of contamination of the environment following the blast at Goure PX Plant in Zhangzhou, Fujian province — the second explosion to hit the factory in 20 months. Hundreds of residents were evacuated from their homes in the surrounding area after the blast on Monday night, while 177 fire engines and 829 firefighters battled the blaze. Scroll down for video . Firefighters battle to extinguish the ferocious blaze at the Chinese chemical plant . Flames rise from the chemical plant in Zhangzhou after the huge explosion on Monday night . It took 177 fire engines and 829 firefighters to bring the blaze under control, officials said . Residents are evacuated from their home in a village close to the fire at the chemical plant . The plant manufactures paraxylene, or PX, a chemical used for producing fibers and plastics. Exposure to the chemical can cause eye, nose and throat irritation. There have been several protests against the chemical plants in China in recent years. Authorities told The People's Daily Online that an oil leak at the plant had caught fire, leading to the explosion of three oil storage tanks at Tenglong Aromatic Hydrocarbon (Zhangzhou) Co. Ltd. on the Gulei Peninsula in Zhangzhou City. Environmental officials are monitoring the surrounding area for signs of contamination . The blaze could be seen for miles, with reports that tremors from the explosion were felt 30 miles away . The plant produces paraxylene, or PX, a chemical used for producing fibers and plastics . Officials said initial tests suggested there had been no contamination of the surrounding enivronment . It was the second accident at the controversial plant in just 20 months . Nine experts were at the site to investigate in the accident. Health authorities said six injured people are being treated in hospital, while another 13  had required medical attention. Environmental protection authorities have dispatched more than 50 personnel to monitor the situation. Officials claimed they had brought the blaze under control this morning. Firefighters examine the damage done by the blaze at the plant . Officials said the blaze had been brought under control by Tuesday morning and that an investigation had begun . The initial explosion was reportedly caused by a leak that ignited three oil tanks . It is the second accident in 20 months at the same facility, owned by Tenglong Aromatic Hydrocarbon (Zhangzhou) Co. Ltd. The plant attracted protests even before it was built. It was slated for the densely populated city of Xiamen in Fujian, but protests in 2007 by residents concerned about potential health hazards succeeded in getting it moved to a less populated area in Zhangzhou. It was reported that tremors from the blast were felt up to 50 kilometers (30 miles) away.
target: Plant in Zhangzhou, Fujian province, is used to make a toxic chemical .
  Nineteen people required medical treatment after blast caused by oil leak .
  Plant produces paraxylene, which can cause eye, nose and throat irritation .
  It is the second accident at the controversial plant in 20 months .
  It took 177 fire engines and 829 firefighters to bring blaze under control .