Quebec provincial police are investigating after a seven-year-old boy handed out pills on a school bus this week, telling other children the pills were candy.

Police said the child attends La Passerelle elementary school in Saint-Paul, on the outskirts of Joliette in the Lanaudière region northeast of Montreal.

The incident happened on Monday, but police only learned about it yesterday.

Sûreté du Québec Sgt. Claude Denis would not confirm whether the pills contained narcotics, where they came from, nor how many children took them.

However, sources have told Radio-Canada that the pills may have been methamphetamine, and that they were given to about 10 children.

Radio-Canada said it has learned one girl was treated in hospital for stomach pain after ingesting the pill she was given.

SQ Sgt. Claude Denis said police investigators are working with the Des Samares school board and youth protection authorities. (Radio-Canada)

'Isolated event'

On Thursday, the Des Samares school board released a statement on behalf of La Passerelle school, with scant details of what actually transpired.

"Following an isolated event that happened on a school bus, the students involved and their parents have been contacted," the news release stated.

Several parents have been critical of how long it took for the board to react to the incident.

However, the school board said it was important for the school's administration to ensure that the students were safe and that administrators had all the facts in hand before they communicated with parents.

"At this time, a police investigation is underway, and rest assured that we are collaborating with authorities," the board said in its statement.

Police said they are working with the school board, as well as with Quebec's Directorate of Youth Protection.