Twenty children and two adults were transported to Charles-Lemoyne Hospital for precautionary reasons after they began to feel ill at a public swimming pool in Varennes Tuesday afternoon.

The incident occurred around 2:30 p.m., when police say chemical products were improperly mixed into the wading pool, said Pierre Tremblay from Richelieu police. Children fell ill due to chaemical fumes which may be attributed to chlorine.

Varennes town manager Sebastien Roy said maintenance was being done at pool about 2:15 p.m. when shortly after, the children were overcome by fumes.

Seven children were transported by ambulance and the others by special bus to the hospital.

They have since recovered and show no signs of illness, though some spent the afternoon and early evening receiving oxygen treatments at the hospital, and were kept for observation.

Trembley said employees evacuated the building and pool area, which is annexed to Le Carrefour high school in Varennes.

The local fire department has sent the list of chemicals to the hospital.

Both the wading and 25-metre pools will be drained, so it is unlikely it will reopen before Thursday.