As Halloween quickly approaches, police departments and other agencies are warning about the possibility of marijuana edibles finding their way into children's trick-or-treat bags.

The Nebraska Regional Poison Center released tips Tuesday to help parents identify dangerous treats containing cannabis. "Marijuana edibles can be found in many shapes and sizes, and they resemble traditional candies in their names and packaging," the center wrote. "This is another good reason to check all your children’s candy when they get home."

The Arizona Poison and Drug Information Center released a similar warning last week, although the center noted:"The number of cases of children harmed by tampered treats is relatively small."

A late-September marijuana candy bust had police advising parents to be on alert for suspicious products in their children's Halloween candy. The Montgomery County Narcotics Enforcement Team executed a search warrant at a Texas home, where agents found a "substantial amount" of marijuana edibles, according to ABC.  The candy had been shipped to the residence across state lines. 

Last year, similar concerns arose in Colorado but ultimately were unfounded. The Denver Police Department issued a warning for parents to be on the lookout for any cannabis products handed out to trick-or-treaters. "With Halloween fast approaching, Colorado citizens are in a unique position in the country -- watching our kid's candy for marijuana edibles," the department said in a statement. 

It posted a video to educate parents about how to identify unsafe handouts.

The Children's Hospital Colorado reported no instances of accidental pot poisonings from the 2014 celebration, according to USA Today.

"For years law enforcement officials have been warning parents to be on the lookout for marijuana edibles in their kids’ trick-or-treat sacks," Forbes contributor Jacob Sullum wrote in 2014. "And for years, as far as I can tell, there has not been a single documented case in which someone has tried to get kids high by doling out THC-tainted treats disguised as ordinary candy."