"This morning, four children and a teacher burned to death when a guard at the nursery school sprayed alcohol on the victims and his own body before setting them alight", the prosecutor of Minas Gerais state, in the country's southeast, said in a statement. The fire gutted the day care centre.
Local media identified the guard as a 50-year-old man who helped with security at the daycare centre since 2008.
According to BBC, Santos poured a flammable liquid over several people inside the day care before starting a fire.
Two girls and four boys, all aged four, were killed and dozens of people were taken to hospital with severe burns in Janaúba, southeastern Brazil. It was also revealed that he was sacked from his position in September. Some of the patients are being airlifted to a specialised burns unit in the state capital, Belo Horizonte. The suspect died of his injuries at the hospital.
Brazilian President Michel Temer expressed his condolences via Twitter.
They also revealed they have opened a line of inquiry into Mr dos santos who is believed to have been suffering from mental health issues, saying they have searched his home and questioned his family and close friends in order to determine his motives for carrying out the devastating attack. "We hope these things will not happen again in Brazil".
Janauba's mayor has declared a seven-day mourning period.