The Broncos were on their way to play a game at 6pm local time on Friday against the Nipawin Hawks of the Saskatchewan Junior Hockey League, CKOM reported.
The Hawks announced on Facebook that the game had been cancelled.
The SJHL is a second-tier junior league comprising players between the ages of 16 and 21.
Canadian Prime Minister Justin Trudeau posted a tweet in which he offered condolences.
"I cannot imagine what these parents are going through, and my heart goes out to everyone affected by this terrible tragedy, in the Humboldt community and beyond," the premier tweeted late Friday.
"We're just waiting to hear,' Rick Shultz, chairman of the board for the SJHL, told the National Post.
"We just know there has been an accident. It's not very good."
"It's one of the hardest days of my life," Kevin Garinger, president of the Broncos, told TSN.
"There have been multiple fatalities - our whole community is in shock, we are grieving and we will continue to grieve throughout this ordeal as we try to work toward supporting each other."
Garinger said the team includes players from Edmonton, Slave Lake and Airdrie in Alberta and from Saskatchewan and Manitoba.
"It's a horrible accident, my God," Hawks executive Darren Opp said in remarks reported by CTV.
"There's uncles and moms and dads waiting to hear whether their sons and nephews are OK.
"This is I would think one of the darkest days in the history of Saskatchewan, especially because hockey is so ingrained in how we grow up here," Henry said.