Five bystanders intervened when a woman was stabbed repeatedly in a Nanaimo park, seemingly at random, on Wednesday night.

Police were called to Maffeo Sutton Park along the city's waterfront at around 10:15 p.m. for a report of a stabbing.

They discovered a 30-year-old woman had been stabbed multiple times, and that five people who were along the walkway at the time came to the victim's rescue.

"It all started when we had 911 calls from near the crab dock by Maffeo Sutton Park. We got on scene and there were at least five bystanders holding the male on the ground," said Nanaimo RCMP spokesman Const. Gary O'Brien.

The woman was rushed to hospital in life-threatening condition, but paramedics and doctors have since managed to stabilize her.

"We want to acknowledge the fact that the five bystanders probably saved this woman's life. Without their assistance, it would have been terrible," said O'Brien. "We don't expect people to do this, but they reacted accordingly and they saved her life."

A 17-year-old man was taken into custody at the scene. Police say he's from the Lower Mainland, but has ties to Nanaimo.

Investigators say the victim and attacker did not know each other and the stabbing may have been random.

Social media lit up as the chaotic scene unfolded, with multiple RCMP cruisers and ambulances responding.

"I heard all these sirens, they were screaming through here," said Nancy McLellan, who lives in a condo overlooking the crime scene. "I looked over and there was about seven different vehicles over here and an ambulance."

Another witness, who wished to remain anonymous, told CTV News that she could see the victim's multiple stab wounds through her binoculars.

"They lift up her shirt and there was like 10 stab wounds on her back. I just couldn't believe I was seeing it," she said.

The suspect is expected to make his first court appearance this week.