An oil tank blew up Wednesday afternoon in northwest China's Xinjiang Uygur Autonomous Region, leaving at least three workers dead, one injured and four missing, local authorities said.

The explosion happened around 4 PM at the Fukang Iron Coke Co. Ltd. in Fukang City, in the Hui Autonomous Prefecture of Changji, said a Xinjiang Autonomous Regional Work Safety Administration spokesman.

In total, 56 fire-fighters and seven fire engines were mobilized to extinguish the fire, which was "soon brought into control," the spokesman said.

The tank contained 2,000 cubic meters of coal tar, a viscous black liquid containing numerous organic compounds used as a roofing, waterproofing and insulating compound and as a raw material for many dyes, drugs and paints.

The leaked coal tar had been properly disposed of by being diverted to safe areas, a company spokesman said. The tank had also been sealed with foam material.

Eight other oil tanks located nearby were not affected and had been cooled down, he said.

Local environmental authorities said they had not detected pollution in the underground water and nearby rivers, but some chemical elements in the air, such as benzene, toluene and dimethylbenzene, had exceeded standards.

They would continue to monitor the air quality.

An investigation team headed by Sheng Shaokun, Xinjiang Autonomous Regional Work Safety Administration deputy director, was probing the accident.

(Xinhua News Agency June 26, 2008)