KING CITY, Ont. -- Police are warning pet owners and parents to be vigilant after poisoned food was allegedly left out in a park north of Toronto.

York Regional Police say two suspects have been identified and potentially tainted bread has been sent to a lab for analysis, but no charges have been laid.

They say a concerned citizen contacted them last Wednesday to report that a woman had been leaving bread and dog food on the ground at King City Memorial Park.

The caller told police he knew of at least two dogs that had eaten something at the park and became ill.

Police say they received another report on Monday from animal control officers in King City, Ont., who provided information on possible suspects.

Officers then found pieces of bread they say have been sent to a forensic centre, as well as empty bags and containers that the suspects were allegedly carrying.