A 30-year-old man is facing numerous charges after allegedly attacking kindergartners with a curtain rod during recess at an East Gwillimbury school, seriously injuring a boy.

York Regional Police say that just before 1 p.m. Wednesday, they were called to Our Lady of Good Counsel Catholic Elementary School on Murrell Boulevard for a report of an assault.

A mother of a kindergartner at the school who did not wish to be identified told CP24 that a man wearing a helmet on his head was walking with a woman near the school at about 12:45 p.m. when kindergartners were outside for their recess.

Two of the three kindergarten classes at the school had already gone inside when the attack happened.

Police say numerous witnesses told them that the man hopped a fence into the penned area where the children were and hit a child with a plastic curtain rod.

The mother told CP24 her son saw the man furiously swinging at children and teachers.

“He just started swinging it at the children,” she said.

Investigators credited the teachers and other adults nearby with diffusing the incident.

“School staff and a good Samaritan were able to remove the weapon from the suspect and get the students back into the school,” Const. Laura Nicolle told CTV News Toronto.

A5 year-old boy who was struck suffered a “serious injury,” according to police.

Parents at the school say the boy reportedly suffered a concussion.

The entire school was placed into lockdown as police and paramedics rushed to the scene.

The suspect, a 30-year-old man, who police say lives with cognitive impairment, was arrested and charged with aggravated assault, assault with a weapon, weapons dangerous and common nuisance — endanger life.

He was held in custody pending a bail hearing in Newmarket.

Nicolle said his name is not being released “due to the other personal information that was released” about him “regarding his cognitve impairment.”

The mother told CP24 that older students who have cell phones began messaging their parents, and she learned of what occurred through messages passed to her from other parents, not the school board.

At 2:53 p.m. that day, the principal of the school, Van Quinn, sent a message to parents, detailing an “incident.”

“There was an incident outside the school in the kindergarten yard that resulted in one of our students being hit by a passerby,” the email read. “This person lives in our community with his family, and has special needs. York Regional Police and Paramedic Services of York Region were immediately called to the school. The injured student was taken to hospital as a precaution, and police are questioning the assailant.”

Investigators say they believe the assault was totally random.

“We are committed to the safety of our students and staff, and will always do our best to work with local authorities in such situations, and to make you aware of these events,” Quinn wrote in the email.

On Thursday, York Catholic District School Board spokesperson Mariann Gordon told CTV News Toronto the board “takes this type of situation very seriously and is deeply concerned that one of our students was injured.”

“The school’s Safety Plan is being reviewed and, if necessary, will be revised to outline additional steps the school and the Board will take to ensure the continued safety of students and staff.”

Gordon also said a support team has been sent to Our Lady of Good Counsel to assist students and teachers in coping with the incident.