A nationwide overhaul of oil pipelines launched after a fatal explosion in Qingdao, Shandong province, has found hazards in many areas that could lead to similar incidents, according to the country's top work safety watchdog.

The overhaul was launched after oil leaked into sewage pipes where it exploded to kill 62 people in Qingdao on Nov 22, and has detected faults such as aging pipes and overlapping pipelines for oil and sewage, said Huang Yi, spokesman for the State Administration of Work Safety.

"Some of the problems are staggering and some hazards are found everywhere," he said, adding that many oil pipelines are more than 40 years old and suffer from erosion and weakening.