The impact of a tanker accident off the South Korean coast turned out to be more severe than previously thought nearly 7,000 people continued efforts Sunday to contain an oil spill, according to dpa. Work to contain the spill would take at least two months, Minister for Maritime Affairs and Fisheries Kang Moo Hyun said. The situation in the affected Taean region, some 120 kilometres south of Seoul, has been declared a catastrophe. A slick at least 17 kilometres long and 10 metres wide oozed from a Hong Kong-registered supertanker after it was hit by a barge off the western coast Friday, spilling an estimated 10,500 tons of its cargo into the Yellow Sea. "It is possible the oil spill will extend further," a spokesman for the coastguard said, adding they had managed to stop more oil spilling by pumping the remaining cargo from three damaged tanks. The ship was now ready to be manoeuvred into the next port, he said. The tanker meanwhile remained anchored some 10 kilometres off the coast on Sunday evening. The Hebei Spirit was eight kilometres north-west of the Taean peninsula waiting to enter port when it was rammed by the unmanned crane-bearing barge which had loosened itself from a tug in a storm. The crane punched three holes into the tanker that had a cargo of 260,000 tons of crude oil. The catastrophe is likely to have serious consequences for the Taean region and its tourism and animal breeding industry. Even if many fish and other sea creatures in the area survived, it would be hard to sell them, Kang said. Taean is a popular seaside resort. The oil slick was also threatening a maritime park, and the area provides important wetland stopovers for migrating birds. Around 100 boats and helicopters were involved in operations to stop the oil from spreading further. Already on Friday floating barriers had been put down, and South Korean television showed people attempting to clear away the layer of oil with spades, buckets and mats. The previous local oil-spill record was set in 1995 when a 144,567-ton tanker, the Sea Prince, struck a reef, releasing 5,035 tons of oil in waters off the south coast. The damage caused then amounted to some 48 million dollars.