Halton Regional police say two officers helped reverse an apparent overdose by two teens who thought they were smoking marijuana.

They say they responded to a call for two unconscious 18-year-old men outside a home in Milton, Ont., around 2 p.m. Wednesday.

The officers gave them naloxone, a drug that can reverse the effects of an opioid overdose.

Police say the teens assumed they were smoking cannabis but lost consciousness and began having seizures.

A neighbour saw the incident and called 911.

An investigation is ongoing and what drugs the teens smoked have yet to be identified.