TOLEDO, Ohio -- Two children have been admitted to a hospital after a chlorine leak at an Ohio child care centre's swimming pool.

Fire officials in Toledo say five preschool students were in the water when the leak was discovered Thursday morning at a swimming pool at the Catholic Club, a child care and family centre run by the Catholic church.

A hospital spokeswoman says three of the five children and two adults were treated and released while the two other children will remain at the hospital. Their conditions weren't released.

Seven other children were treated at the child care and family centre.

Toledo's fire chief says the leak came from a tank used to treat the swimming pool.