According to Leicestershire Police, the victim had previously had contact with the children, but did not say the reason for the contact.
In England, five children have been arrested on suspicion of murdering an 80-year-old man, British media reports.
The retired man had been walking his dog in a park in Leicestershire on Sunday evening when the children attacked him. The victim died of his injuries at the hospital on Monday evening, the police say.
of The Guardian three of the children are 12 years old and two are 14 years old. The police believe that they fled the scene immediately after the assault.
According to Leicestershire Police, the victim had previously had contact with the children, but did not say the reason for the contact.