ST. JOHN'S, N.L. -- Worried parents rushed to a St. John's, N.L., high school Wednesday after as many as 20 students were hit with a harsh spray irritant during an altercation.

Police said "at least one student" at Prince of Wales Collegiate was taken to hospital, and between 15 and 20 people were affected after being caught in the aerosol spray.

Police described it as "possibly bear spray or pepper spray-type product."

Multiple ambulances were called to the scene, and paramedics treated students for minor, temporary injuries.

The Royal Newfoundland Constabulary could not confirm what weapons were used in the altercation aside from the spray, and students who witnessed the incident described seeing an orange can.

Const. Geoff Higdon said police were unable to confirm what other weapons were used, but noted that investigators did not find evidence of a firearm on the property.

One student who did not want to be identified said he followed a large group of people shouting in the back parking lot, and said he saw the spray deployed when one group of people were surrounded by a group who "picked things up off the ground."

Another student who said he was a few feet away from the altercation said he couldn't open his eyes after being hit with the spray.

The school was still in secure mode as of early Wednesday afternoon, but parents were on site picking up their children after hearing about the incident through word of mouth and social media.

One mother who arrived at the school shortly after noon said she was at work at the hospital when she heard the alert go out about a situation at the school, but soon got in contact with her son who was safely inside a classroom.

Another parent, who also did not want to be identified, said she was alarmed when she saw posts about the incident on social media, but was quickly relieved when her two children texted her confirming they were safe.

"Thank God for phones in this day and age," she said.

The RNC said the investigation is ongoing.