LOWELL (CBS) — There has been a surge in opioid-related overdoses in the Greater Lowell area, the Lowell Fire Department said midday Tuesday. Twenty-one overdoses have been reported in the last week, and eight in the last 24 hours.

The fire department said, “There appears to be a lethal, very strong batch of opiates in the area.”

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Over the weekend, there were three suspected fatal overdoses.

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Fentanyl can be mixed in with heroin, cocaine, and sold as a pill.

“We strongly urge people not to use opiates, but if you or your loved one is suffering from addiction, please be extra vigilant in the coming days,” said the department.

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They also warned to not use alone and check on loved ones who may be using drugs. Call 911 if you see a possible overdose.