Traffic was backed up on Circle Drive Wednesday after a three-vehicle crash involving a cement truck, a bus and a semi-trailer.

The collision occurred at approximately 4 p.m. on Circle between 33rd Street West and Laurier Drive.

“Initial investigation shows a cement truck struck the back of a chartered passenger bus, which then struck the back of a semi-trailer,” police said.

Police said all injuries were minor -- or non-life-threatening. The driver of the bus told CTV that she and three passengers were sent to hospital. She broke her arm in four places.

All of the passengers on the bus were adults.

Southbound traffic on Circle Drive was delayed as trraffic was reduced to one lane while police investigated and the collision scene was cleaned up.