Beijing: The death toll in the twin oil pipeline explosions in east China today rose to 55 as authorities blamed human errors for one of the worst industrial accidents in the country.
Search and rescue operations were still in progress as nine people still remained missing, three days after the blasts which caused extensive damage.
About 136 injured people injured in the blast are being treated in various hospitals.
The blasts exposed three severe problems of human errors and the accident was a "very serious dereliction of duty", a senior official in charge of the country`s work safety, said.
The problems include the unreasonable layout of oil pipelines and urban drainage pipes, negligence of duty on pipeline supervision and unprofessional handling of oil leakage before the blasts, Yang Dongliang, director of the State Administration of Work Safety was quoted as saying by the state-run Xinhua news agency.
Yang made the remarks in Qingdao City at a meeting of an investigation team that is probing the accident.
Meanwhile, Qingdao?environmental protection authority said the oil spill into the sea and underground water has been basically brought under control. Barriers have been erected around the contaminated areas along the coast line.
For its part the oil refinery Sinopec denied earlier reports that the exploded pipeline was put into operation just this August.
It said the pipeline was in use for 27 years, linking Huangdao with the city of Dongying.
The blast causing extensive damage to life and property raised questions about the safety of the pipelines laid in civilian areas.
This particular pipeline which was built beneath the road destroyed the vehicles plying on the road besides causing extensive damage to the buildings around.