Worcester officials are warning drug users in the city to avoid heroin after at least nine drug overdose deaths since Friday.
Public health officials issued an advisory Wednesday that there may be contaminated heroin on the street. People are urged to call 911 if they see a drug overdose.
Police Chief Gary Gemme said heroin is suspected in at least eight deaths. The ninth was discovered Wednesday. He said significant resources are being devoted to finding the deadly drugs.
Three men police believe died from overdoses were found in an apartment Monday.
Authorities say the city is on track for more than 500 drug overdoses this year. Massachusetts and other states have been battling an increase in heroin overdoses and opioid addiction. Gov. Deval Patrick has declared it a public health emergency.