Rescue crews are searching for three men whose boat capsized and sank in the waters off Tofino, B.C. in the early morning hours Friday.

The Joint Rescue Coordination Centre said five people were on board when the six-metre vessel overturned at around 3 a.m., but two of them are accounted for.

One managed to swim to shore and was located at around 4:20 a.m.

A Canadian Coast Guard vessel responding to 911 calls from bystanders scooped another man out of the water at around 3:30 a.m. According to the JRCC, he was not wearing a life jacket.

"Calls for help were being heard from the shoreline close to Duffin Cove," Lt. Melissa Kia of the JRCC told The Canadian Press.

Local business owner and resident Jae Valentine said she heard cries from help in the night.

"I could hear some voices and the voices got louder and I heard someone yelling 'Help. Help. Help,'" she told CTV News.

But Valentine said it was dark and she couldn't tell where the sounds were coming from.

"(I) heard my neighbour yelling at someone saying what kind of help do you need," she said. "I called my neighbour. She said somebody's in distress. Call 911, which I did and the person just continually (said) 'Help me. Help me. Help me.'"

The condition of the two confirmed survivors is unknown, but one was treated by paramedics in Tofino and the other was taken to hospital.

The other three people remain missing in an area of water that covers 41 square kilometres, according to the JRCC.

Tofino RCMP say the survivors have told them they were in a metal-hulled boat with three other man.

Authorities don't know what caused the boat to capsize. The JRCC said the vessel didn't send a distress call before sinking.

"When things like this happen, it's just awful, said Tofino Mayor Josie Osborne. "It's terrible but it does pull the community together."

Osborne said the three missing men are all members of the Tla-o-qui-aht First Nation.

Two helicopters and at least two boats were dispatched to scour the waters, and many locals are also helping with the search.

With files from CTV Vancouver's Maria Weisgarber and The Canadian Press