The cause or circumstances around the crash were not immediately clear, but the bus driver was taken into custody by Laval police, the Canadian Broadcasting Corp reported.
Details of the injuries or the children's ages were not immediately available, but CBC said that about 80 kids under the age of five attend that daycare facility.
"It's terrible what happened this morning in Laval ... all my thoughts are with the children, with the parents and with the employees," Quebec Premier Francois Legault said.
Laval is located about 30 kilometers (18.6 miles) northwest of Montreal in Quebec, Canada's second most populated province.
(Reporting by Ismail Shakil in Ottawa; Editing by Bill Berkrot)
