A whale-watching company is sharing images of a rare and “epic” tussle between a group of orcas and humpback whales off the coast of Vancouver Island.

Paul Pudwell, co-owner of Sooke Whale Watching, posted a video of the incredible encounter to Facebook on Aug. 7.

He said his group came across three transient killer whales off the coast of Jordan River, first seen killing and eating a harbour porpoise.

The orcas then turned their attention to a nearby humpback whale calf, as stunned whale watchers looked on.

Capt. Mark Malleson of Prince of Whales Whale Watching observed the rare encounter, calling it a “great interaction.”

“I’m not sure if the killer whales ever thought they were going to be able to take one of these humpbacks out, but it appears they certainly enjoyed getting them worked up,” he said.

For a few tense moments, it was unclear whether all of the powerful mammals would make it out of the brawl alive.

“At one point, not far from our boat we saw what we thought at the time was a large blood burst and seconds later a humpback, possible the calf, rose and remained stationary at the surface for a few minutes,” said naturalist Valerie Shore of Eagle Wing Tours.

“We all gasped thinking that it was a massive wound, but Mark radioed later that it was whale poop. Maybe it was a defence mechanism like octopus and squid use. More likely, it was a very frightened humpback.”

Department of Fisheries and Oceans whale researcher John Ford said he’s been studying the whales of B.C.’s coast for 40 years, and has only seen one other similar encounter in the wild.

He said while transient killer whales are competent mammal hunters, it’s extremely rare to see them take on humpbacks.

“Humpbacks are particularly formidable prey when they’re large and adult. They will go after calves or even juvenile humpback whales because they’re not as dangerous in their defense,” he said. “Their appendages are encrusted with barnacles. Essentially they’re like brass knuckles, and it’s just a dangerous thing for killer whales.”

Those who witnessed the event said the adult humpbacks eventually forced the transients to retreat.

The calf was spotted after with what some thought was a torn tail, but the whale watchers said they were too far away to confirm.

The showdown comes during a year of unprecendent humpback whale activity off B.C.’s southern coast.

A July 9 video of a group of whales lunge feeding off Victoria was the most humpback activity observed in the region in nearly a century.

The species’ comeback could be due to changes in oceanographic and ecological conditions resulting in increased food sources, scientists said.