The Nam Dan District Department of Education said he had been studying at home wearing earphones on Thursday afternoon when the phone exploded.
Severely burned, he was rushed to hospital for emergency care but tragically died that night.
Nguyen Hong Son, chairman of Nam Dan District, said the boy’s family has not sought an investigation.
The district reopened schools over a month ago, but in order to be prepared in case of a sudden closure, authorities require them to have online classes one day a week.