Three orphaned grizzly cubs are being cared for at the Calgary Zoo.

The young bears were discovered by Alberta Fish and Wildlife officers in the Crowsnest Pass.

"Our conservation work extends around the world, but we never miss a chance to lend our expertise close to home," the zoo said in a post on Facebook announcing the new arrivals.

Zoo officials believe the mother bear was killed by someone in the region.

"Efforts are underway to find the three little bears a suitable permanent home, until then, the Calgary Zoo team will be giving them lots of love and care," the zoo said.

Grizzly bears are a threatened species in Alberta. The cubs would not have survived without human intervention, the zoo says.

"We strongly believe that science and animal welfare best practices support these orphaned grizzly cubs going to an appropriate zoo," said the zoo in reply to a comment on Facebook suggesting the bears be returned to the wild.