A 29-year-old woman is facing multiple charges after police say she allegedly attempted to drown her toddler at a beach near Rotary Park in Ajax.

On Feb. 9 at around 4 p.m., a bystander spotted a woman behaving strangely and holding a small child on the railing of a bridge near the park, located in the area of Parkes Drive and Lake Driveway West.

According to police, the passerby engaged the woman in conversation and walked with her and the child toward a parking lot in the area.

“It was just odd behaviour, the citizen was just concerned a child that young being perched on the rail overtop of moving water and it's very cold out,” Durham Regional Police spokesperson Dave Selby told CTV News. “The bystander walked with the mother and child off the bridge but then noticed they were headed toward the beach.”

Selby said the bystander and a second member of the public then saw the woman standing in thigh-deep water and holding the three-year-old boy underwater. Both citizens then rushed to the aid of the child.

The boy was brought to shore, wrapped in warm clothing and later taken to hospital for treatment.

He was released into the custody of his father and the child’s mother was apprehended under the Mental Health Act.

Speaking about the incident, Selby praised the two bystanders who rushed in to help the child when they realized what was happening.

“Here's two complete strangers that decided to get involved because something didn't look right so we really tip our caps to them because that was fantastic what they did,” Selby said.

The 29-year-old Ajax woman has been charged with attempted murder, aggravated assault and failing to provide the necessaries of life.

To protect the identity of the child, police are not releasing the name of the mother.

Anyone who may have witnessed the alleged incident is asked to contact Det. Ahee of the Major Crime Sexual Assault and Child Abuse Unit at 1-888-579-1520, ext. 5234.