Le Figaro reported that the first incident took place in the Parisian suburb of Courbevoie.
The father of one-year-old Iliam had told creche managers he would be slightly late. When he arrived at the creche shortly after 7pm, he found the building locked up and noone around.
His child had been left inside with noone looking after him.
"That should never have happened," said the boy's mother. "If they had proper security processes they would have noticed straight away that a child was there."
The boy's father alerted police who were able to get into the building. Baby Iliam was fast asleep and not harmed.
The next day, in Bordeaux, a two-and-a-half-year-old toddler was able to get out of his creche through an open door.
The boy found himself on a busy street where he avoided being knocked over by a car.
The driver informed local authorities and a beautician working across the road took him in to look after him.
The boy's mother told local newspaper Sud Ouest she was furious.
"It's unacceptable," she said. "My boy could have been killed. There are four doors they need to get through to get outside and they all have handles high up so children can't reach them."
The director of the Bordeaux creche has been relieved of her responsibilities while an investigation takes place.