Four people have died from drug overdoses within a period of 24 hours, Windsor police say.

"We were required to assist paramedics with several fentanyl overdoses as of yesterday, and over a period of 24 hours we had five people deceased," explained Staff Sgt. Karel DeGraaf.

Police originally reported five people had died. On Monday they said one person survived.

"They're drug overdoses, and they're believed to be fentanyl-related deaths," said DeGraaf, adding that confirmation is to be done through the coroner's office.

"It's an abnormality for one 24-hour period."

Police were not able to say how many overdoses they responded to in total, and they are not issuing warnings at this time.

"This is just information for people to be aware of the circumstances of it and to obviously be safe."

Last year, there were 36 opioid-related deaths in total for Windsor-Essex. There were 18 in 2014, 25 in 2015 and 37 in 2016.