A seven-year-old boy has been handcuffed and removed from his school after repeatedly punching his teacher and grabbing her hair.

School officials say they followed protocol and that the child was restrained following aggressive behaviour.

The boy's mother, Mercy Alvarez, has claimed her son was subject to "police abuse" - and a video she recorded in the aftermath has been viewed nearly three million times.

"My heart's been broken," she said.

On Thursday, the teacher at the kindergarten in Miami, Florida, had told the boy to stop playing with his food and removed him from the cafeteria when he refused.

According to an incident report, the child hit the teacher repeatedly in the back - and continued punching and kicking her until they both fell on the ground. He then acted aggressively towards a police officer.

The seven-year-old had also punched students and staff members during another incident in November.

He was briefly hospitalised at Miami Children's Hospital under the Florida Mental Health Act following the latest incident, amid fears he could pose a threat to himself and others.

Although it was reported in local media that the boy was arrested, a school district spokeswoman later said he had been "restrained for transport".

Officials said the incident was seen by witnesses and caught on CCTV, and that the child's father had given permission for a psychiatric evaluation.

Image: Facebook/Mercy Alvarez Alvarez

His father Roland Fuentes said he had been "in shock" after being called in after the incident.

"(They said) you know he's a danger to society," he said. "I said what? Seven years old? A danger to society?"

Ms Alvarez has said her son does not have a mental disorder, adding that he had behaved well and earned good grades in previous years.

She asked: "If my child wasn't aggressive anymore when we got there, like they were saying he was before, why take such extreme measures?

"This is too much for a boy that age to go through. It can't be a normal procedure."

Ian Moffett, the school district's police chief, said it was rare for children of such a young age to be involuntarily institutionalised for a psychological evaluation, but that it was deemed necessary in the circumstances.

A statement said: "This action was warranted to prevent his erratic and violent behaviour from bringing further harm to others or himself."

The teacher is planning to press charges, and the district's professional compliance unit is currently investigating the incident.