The collisions began around 6:30 p.m. Wednesday, when a bus carrying seniors hit a stopped transport truck on the Coquihalla Highway in white-out conditions outside of Kamloops, the Royal Canadian Mounted Police said.
A second semi was unable to stop on the ice and hit the bus from behind, the Kamloops Daily News reported.
At least two other vehicles smashed into the crash scene, the report said.
Eight ambulances and various fire vehicles responded to extricate victims from the bus and trucks. Firefighters worked at neutralizing leaking diesel fuel, the newspaper said.
Five of the crash victims had serious injuries and the other 22 were treated and released, police said.
Traffic in both directions was at a standstill for more than 3 hours while crews cleared the wreckage, the newspaper said.