An explosion at an oil refinery in an industrial area of Bangkok sparked a massive fire early Wednesday, sending a thick column of smoke into the air that could be seen across the Thai capital. No one appeared to have been injured in the blaze, which began after a loud blast at around 7.30 am local time (0030 GMT), according to a spokeswoman for the refinery firm. \"We are investigating the cause of fire and will inform the public immediately,\" said Chaveewan Kiatchokchaikul of Bangchak Petroleum, who said the fire had been brought under control. Emergency services deployed to the scene said there had been no casualties reported so far. \"There is not much oil so people should not panic,\" said a local Bangkok fire fighter on Thai television. The Bangchak oil refinery, which employs around 600 people, is located in a large industrial estate in a sprawling suburb. It is among the country\'s biggest refineries and 120,000 barrels of oil are processed at the site every day, a company official told AFP.