Authorities in Keshena, Wisconsin, are investigating the discovery of a packet of crystal meth mixed in with a child's Halloween candy, according to news reports.

It happened on the Menominee Indian Reservation on Sunday night and tribal leaders are warning parents to be extra vigilant.

"It looked like a crystal-type substance, subsequently was tested and confirmed it was methamphetamine," Ben Warrington, the tribal emergency management coordinator told WLUK-TV.

Police said they do not know whether someone intentionally handed out the meth or whether it was a mistake, WLUK-TV reported.

The drugs were in a small, yellow bag about the size of a quarter.

Tribal leaders are asking parents to drop off their children’s Halloween candy at designated locations out of an abundance of caution.