07/16/2015 06:44 EDT | Updated 07/16/2016 05:59 EDT

Surrey RCMP issue warning after multiple drug overdoses

Police in British Columbia are advising drug users to be cautious, after at least eight people in Surrey overdosed on drugs within 24 hours.

Surrey RCMP said the drug ingested was thought to be heroin, but analysis has not yet been done to confirm that no other substances were involved.

Police said the affected people showed immediate signs of overdose, and in three cases, "extreme life saving measures" were necessary.

All the overdose victims were taken to local hospitals and are now recovering, according to police.

Police have not yet said whether the drug fentanyl is believed to be involved, as it was in past overdose warnings.