The news was confirmed by the Porto criminal court as well as by the victim’s family.
He passed away at the São João do Porto Hospital on Monday night following 48 hours in a serious condition.
The 16-year-old suspect was detained by police and faces charges of attempted murder, which could now be changed as a result of the victim’s death.
Police said the incident happened between 10pm and 11pm on Saturday night. The younger boy is believed to have been attacked by the older teen with a knuckle duster.
Witnesses who knew the two claim there had been bad blood between the pair for a while.
In a statement, PJ police said the suspect “violently beat the victim around the head” and that the boy had “fallen lifeless on the ground, and was immediately transported to the hospital.”
Reports published shortly after the victim was taken to hospital wrongly announced his death, though that information was quickly corrected.
At the time police said the erroneous information came from a non-official hospital source.