LOWELL, Mass. (AP) — Lowell officials say there has been a spike of opioid overdoses in the city: 20 overdoses in three days.

Fire Chief Jeff Winward tells the Lowell Sun that the only reason none of the overdoses since Friday were fatal is because first responders were able to get there to administer the opioid antidote Narcan in time.

Officials are worried that the spike is due to a deadly batch of heroin or fentanyl in the area.

Winward is asking people not to use illegal drugs, but says if they do, to have Narcan handy . He's also asking anyone who witnesses an overdose to call 911 right away.