Four children died after a security guard doused a nursery with alcohol and set it on fire.
The victims were aged one to four. A childcare worker was also died in the blaze.
Several others were injured at the nursery in the city of Janauba in eastern Brazil.
The 50-year-old guard is alive but is in a serious condition.
He had worked at the centre, which cares for around 70 children, since 2008
Firefighters said the motive of the attack was unclear.