NORTHUMBERLAND COUNTY, Ont. -- Provincial police are warning that a synthetic drug known as "Flakka" is believed to be circulating in Northumberland County.

They say the drug is being sold on the streets as Xanax.

Police say Flakka is a designer drug that can be snorted, smoked, injected or swallowed and has been found combined with other drugs such as marijuana.

Symptoms of Flakka use are often delayed, occurring up to 18-24 hours after ingestion, and can include extreme agitation, hallucinations, psychosis, hyperactivity, delirium, bizarre behaviour and extreme strength.

OPP say the side effects include acute kidney injury, heart failure and even death.

Const. Kimberly Johnston says anyone who encounters a person who appears to be in a state of overdose should exercise extreme caution and immediately call 911.