Two children died and six others were injured on Wednesday morning after a bus ran into a daycare center in the Montreal-area suburb of Laval, police said.

The bus driver, a 51-year-old employee of the Laval municipality’s public transit system, was arrested for homicide and reckless driving, police spokesperson Erika Landry said.

The cause or circumstances around the crash or the children’s ages were not immediately clear.

“We’re talking about serious injuries, some are critical,” an ambulance official told reporters in Laval earlier.

About 80 kids under the age of 5 attend that daycare facility, local media reported said.