Health authorities in north China's Shanxi Province announced Thursday the preliminary result of an investigation into a media report alleging defective vaccines had killed or sickened 78 children in the region.

Investigators from Shanxi Provincial Health Department have found the families of 10 out of the 78 children reported by a Beijing-based newspaper, China Economic Times, Wednesday, Li Gui, chief of disease prevention and control section of the department, told Xinhua in an exclusive interview.

The investigators confirmed that only one child who showed adverse reactions and died was diagnosed as being related to vaccines, but this case was not caused by the problematic vaccines on which the report had blamed, Li said.

He didn't make further comments on the number of children affected or their situation described in the report.

In Wednesday's report, the China Economic Times named 15 children out of 78 that received vaccines including encephalitis, hepatitis B and rabies at different times. Four children died between 2007 and 2008, and 74 were sickened.

The report said that Shanxi Province had been selling problematic vaccines since 2006, causing viral encephalitis after vaccination.

The report accused Shanxi Center for Disease Prevention and Control of exposing vaccines to heat in summer causing quality problems.

Shanxi Health Department Wednesday denied the accusation and announced to launch investigation into the case.

China's Ministry of Health (MOH) has also launched an investigation into the case, said a statement on the ministry website Wednesday.