A young child was severely injured after he was thrown from a horse when a smirking woman spooked the creature by pulling its tail.

Disturbing footage capture the moment Meri Fuerte's five-year-old son was bucked from a horse along a trail in Daly City, just south of San Francisco, on February 23.

Fuerte's family was on an outing at Ocean View Stables when the stranger startled the horse, according to KTVU .

Video showed Fuerte's son riding the animal with the help of an aide as they passed the woman and a man standing along the trail.

Then the woman walked behind the boy's horse and pulled it's tail, causing the boy to be flung off the steed.

She could be seen smirking at her callous act of cruelty as the horse began to buck and disaster ensued.

Fuerte told the local news station the pair of strangers laughed about what happened, then walked away without being stopped.

She said her son suffered a fractured leg and a severe hematoma from the fall, and his medical bills are stacking up.

Ocean View Stables filed a report with the police and told KTVU the family never told them the boy was hurt.

'They denied all medical intervention, and said the child is okay.

So in that situation we ask 'Do you want to get back on' that's always the cowboy way of doing it, you wanna get back on.

'They said yes, so the child got back on,' said Barn Manager Caroline Reed.

'From the time that it happened until the family ended up fully leaving was about an hour, and during that hour the entire hour that child was running around our property.

'We have the footage of that, him playing with his sister. There was no limp in these videos.'

Video showed the boy walking with his sister after the incident, but Fuerte said he didn't display any signs of being injured until later.

Family members shared the footage of the incident on social media to ask for helping finding the woman.

'This lady out of nowhere thought it was funny to pull the horse tail while kids were riding on it and ran away after doing that. Now my cousin is unable to walk from the pain and he has bruises all over his body,' one family member said.

The tail yanking woman has yet to be publicly identified, but KMPH reported she was eventually arrested.

Fuerte told the outlet she was frustrated to learn that the woman was released a few hours later after posting bail.

'I also didn't think it was fair that she made bail in three hours and lived her life free, knowing that she could have caused the death of a person,' she said.

The single mother said she is worried the woman won't receive any punishment.

She has had to take time off work to make sure her son stays off his leg so he can heal.

DailyMail.com has contacted the Daly City Police Department and Ocean View Stables.