China is rushing to keep an oil spill from reaching international waters, while an environmental group tried to assess if the country's largest reported spill was worse than has been disclosed.
Crude oil started pouring into the Yellow Sea off a busy north-eastern port after a pipeline exploded late last week, sparking a massive 15-hour fire. The government says the slick has spread across a 70-square-mile stretch of ocean.
The pipeline is owned by China National Petroleum Corp, Asia's biggest oil and gas producer by volume.
Images of 100ft-high flames shooting up near part of China's strategic oil reserves drew the immediate attention of President Hu Jintao and other top leaders. Now the challenge is cleaning up the greasy brown plume floating off the shores of Dalian, once named China's most livable city.
The cause of the blast was still not clear.
The environmental group, Greenpeace China, shot several photographs at the scene on Tuesday before their team was forced to leave. They showed oil-slicked rocky beaches, a man covered in thick black sludge up to his cheekbones, and workers carrying a colleague covered in oil away from the scene.
The state-run Xinhua News Agency reported a 25-year-old firefighter, Zhang Liang, drowned on Tuesday after a large wave pushed him into the sea amid the clean up. Another man who also fell in was rescued. It was not immediately clear if either were the ones shown in the Greenpeace photos.
Activists said it was too early to tell what impact the pollution might have on marine life.
Officials told Xinhua they did not yet know how much oil had leaked. It was not clear how far the spill was from China's closest neighbour in the region, North Korea.
Dalian's vice mayor, Dai Yulin, said to Xinhua that 40 specialised oil-control boats would be on the scene along with hundreds of fishing boats. Oil-eating bacteria were also being used in the clean up.