CHILLIWACK, B.C. -- The president of Fraser Health is warning there has been an increase in overdoses in Chilliwack.

Dr. Victoria Lee shared an overdose alert on social media saying a bluish-green substance is being sold as fentanyl and is contaminated with benzodiazepines.

The Fraser Health alert says that naloxone may not fully reverse effects of an overdose and people should not wait to call 911 if someone is overdosing.

It also urges people not to use drugs alone where possible so that someone is able to respond in the event of an overdose.