The four-year-old took his leave from his pre-school, crossed several heavily trafficked streets and knocked on the door of his home, much to the astonishment of his mother, who luckily had been working from home on Monday.

When she called her son’s pre-school in central Gävle in northern Sweden, she learnt that staff hadn’t noticed that he had escaped.

Staff now plan to report the incident to the authorities. The Swedish Schools Inspectorate (Skolinpektionen) are already busy investigating a similar incident involving another pre-school in the town.

In a separate incident in the eastern Sweden town of Norrköping, a five-year-old could not be found when his mother came to collect him and his little sister.

Staff at first concluded that he must have made a run for it, but he was later found sleeping in a snow drift outside in the garden.

“He had been asleep outside for several hours. I don’t know if I can trust the staff again,” his mother told the Norrköping Tidningar daily.

According the head of the pre-school, the matter is being treated very seriously and routines are set to be reviewed.