Three horseback riders in P.E.I. got a scare Saturday when they heard what sounded like a warning shot nearby.

The riders were out exercising their horses along McCourt Road in South Granville, in Queens County.

One rider, who didn't want to be named, told CBC News they heard gunfire.

"We heard shots … just bang, bang, bang."

The sound spooked the horses. One rider fell off and was trampled by another horse.

"No one was seriously hurt, but the (rider who fell off) says she should have gone to the hospital because her leg is all swollen."

The riders, all under the age of 25, are with Handibear Hills Horse Sanctuary, which cares for abandoned horses.

They believe someone was trying to scare their horses and wasn't necessarily aiming at them.

"They could have been just shooting up in the air."

Yogi Fell, owner of the horse sanctuary, said there is a shooting range nearby, but the horses are used to that sound. Hunting season is still a month away, she noted.

The RCMP is looking into the matter.

RCMP said it's possible that it was fireworks. Officers looked for empty shell casings but didn't find any.

Fell said something like this has never happened before. She worries about the safety of the riders.

She said she hopes someone comes forward with information.