Seven days after two crude oil pipelines exploded in Xingang port on China's northern coast, the oil slick has spread to over 360 square miles, according to Chinese media.

Although the slick is only one-tenth the size of the 3,000 square mile blanket of oil that has covered the Gulf of Mexico, its impact is likely to be severe. One rescue worker has already died after falling overboard and being sucked into the oil and all fishing off the coast of Dalian has been banned until the end of the year.

Clean-up workers were woefully unprepared for the task in hand, with some using their gloved hands, plastic bags, straw mats and even chopsticks to remove oil from the water.

Oil has penetrated at least 12 inches into the sand at Poshiwan Beach.

Government officials hope to finish the clean-up over the weekend, but experts have warned it could take far longer, with long stretches of shoreline now contaminated.

"Our priority is to collect the spilt oil within five days to reduce the possibility of contaminating international waters," said Dai Yulin, vice mayor of Dalian. More than 800 vessels are working 14-hour days to clean the sea, many of them equipped with special oil-eating bacteria, grown by a Chinese company.

"The use of the oil-eating bacteria at the Dalian spill is the first time we have used biotechnology to solve an environmental pollution problem," said a spokesman for Micro-cleaner Biotechnology Corporation in Beijing. The bacteria break down the toxic hydrocarbons in oil into less harmful compounds. They were used after the Exxon Valdez spill in Prince William Sound, Alaska, in 1989.

An investigation into the cause of the blast has found that a chemical used to remove sulphur was wrongly pumped into pipelines unloading the crude from a tanker, triggering the explosion.