"A large-scale work safety check should be launched ... with inspectors going deep into the production sites anonymously and unannounced," Xi was quoted as saying Sunday by China's official Xinhua News Agency.
An oil pipeline operated by China Petroleum & Chemical Corp., known also as Sinopec, exploded Friday in eastern Shandong province. Xinhua reported crude oil leaked from an underground pipeline before the fatal explosion.
No cause was given for the blast, which damaged the region's storm drainage system as well as oil, gas and water pipelines.
Xinhua published a statement from Sinopec, which expressed its "sincere condolences to the victims." The company vowed to work with regulators during the investigation into the explosion.
The 150-mile-long pipeline, called Donghuang II, went into service in 1986. It can carry 73 million barrels of oil per year, officials said.