Police departments in both Ontario and Alberta are warning parents and children to be vigilant after receiving numerous reports of Halloween candy that was allegedly tampered with.

The Niagara Regional Police first issued a warning on Nov. 1, after local parents reported finding a metal blade in candy given out in Thorold, Ont.

Then, on Nov. 2, police say they attended to a second residence in the Niagara Region, where another razor blade was found in an O'Henry chocolate bar.

According to a police statement, somebody in the north end of St. Catharines, Ont., handed the candy to a child on Halloween night.

When the child returned home from trick-or-treating, they bit into the bar and discovered metal inside.

The child removed the chocolate from their mouth and discovered a blade.

While police say the child was unharmed, they are reminding parents to carefully inspect their children's candy and make sure the wrapping is intact and hasn't been tampered with.

Officers continue to investigate the source of the candy and razor blades, and ask anybody with information to call the police, or to anonymously leave a tip with Crime Stoppers at 1-800-222-8477.

In Toronto, police alerted the public to a “mischief investigation” after parents who were checking a Halloween loot bag allegedly discovered a thumb tack pressed into a chocolate bar.

A statement from police said the incident occurred in Toronto’s east end, in the Eastwood Road and Woodbine Avenue area. No injuries were reported.

Toronto police are asking anyone with information to call 416-808-5500, or Crime Stopped at 416-222-TIPS.

Meanwhile, Alberta RCMP are also probing five complaints of Halloween candy that was allegedly meddled with.

One child in in Lloydminster, Alta., reportedly noticed a white pill after biting into a Snickers chocolate bar.

The candy wrapper appeared to have been opened and resealed.

Other trick-or-treaters also reportedly found packages of pills and a loose capsule mixed in with their bags of goodies.

RCMP say there are no reports of children getting sick, but urge parents to be vigilant and check all Halloween candy.

They added that parents should throw out any homemade treats collected by their children.

With files from The Canadian Press