Crews start clean-up of oil spill off China's Qingdao port by Reuters Share: By Muyu Xu and Roslan Khasawneh BEIJING/SINGAPORE, April 28 (Reuters) - Clean-up crews worked on Wednesday to contain an oil spill in the Yellow Sea near the Chinese port city of Qingdao, a day after a collision between a tanker carrying around a million barrels of bitumen mix and a bulk vessel in thick fog. A preliminary study estimated about 500 tonnes (3,420 barrels) of oil had been spilled but this needs to be assessed further, a Shandong Maritime Safety Administration official who declined to be identified told Reuters by phone.