Investigators in Durham Region say they fear that seven males who suffered overdoses after ingesting cocaine so far this weekend did so because their drugs were laced with fentanyl.

On Friday, June 9, Durham Regional Police say three men went to a gazebo in Cullen Gardens off Taunton Road East and took cocaine. They each quickly fell to the ground and were unresponsive.

A friend called emergency services and police and paramedics rushed all three to hospital. Two men were given Naloxone, a drug designed to reverse the effects of an opioid overdose.

The third man regained consciousness on his own.

That same night, police were called to a home on Thomas Street in Oshawa to help paramedics revive three males who had taken cocaine and were suffering suspected symptoms of overdoses. One of the men had fallen unconscious.

They were each taken to hospital and are expected to survive.

Early Saturday morning, a seventh male took cocaine and appeared to suffer an overdose in Oshawa. He was taken to hospital and expected to survive.

Drug investigators are working to see if the cocaine ingested in these three separate incidents was laced with fentanyl.

Fentanyl is a power opioid considered to be 50 to 100 times more potent than morphine. It can be absorbed through simple contact with skin.

Opoids killed at least 2,458 Canadians in 2016, federal data released last week suggests.

Anyone with information about these incidents is asked to call police at 1-888-579-1520, ext. 5805.