The idea that police officers should use handcuffs and leg shackles to control an unruly individual is hardly unusual in the US, where fondness for the use of metal restraints runs through the criminal justice system.

What is unusual is when the individual in question is five years old, and the arrest takes place in an elementary school.

New York state police were called last week to the primary school in Philadelphia, New York, close to the Canadian border, after staff reported that a pupil, Connor Ruiz, was disruptive and uncontrollable. When officers arrived at the premises, they placed the five-year-old boy in handcuffs, carried him out to a patrol car and put his feet into shackles before taking him to a medical center for evaluation.

The child's mother, Chelsea Ruiz, told the local Watertown Daily Times she was shocked and angered by what had happened.

"An officer told me they had to handcuff his wrists and ankles for their safety," she said. "I told him that was ridiculous. How could someone fear for their safety when it comes to a small, five-year-old child?"