The death toll of an oil pipeline explosion on Friday in the port city of Qingdao has risen to 52, with 11 people still missing, The Wall Street Journal reported, citing a statement by the Qingdao government. A total of 136 people were injured in the blast, with 10 in critical condition. Petroleum from the pipeline, which is owned by Sinopec (600028.SHA), has contaminated some 3,000 square meters of water and 18,000 people have had to be evacuated. Sinopec chairman, Fu Chengyu, has apologized and said it was cooperating with authorities in investigating the causes of the blast.