Seven people have died from overdosing on illicit drugs in the past week alone on Vancouver Island, Island Health said in an urgent warning to drug users Friday.

Four of those fatal overdoses occurred on the South Island over a period of 72 hours, it said.

The health authority is now urging drug users to avoid using alone and to make sure they’re near someone who can help if they suffer an overdose.

“While vulnerable, street-entrenched individuals are still very high risk for overdoses, we are finding that recent overdose deaths involve individuals who are in housing, whether that be a private residence or publicly-funded housing facilities, including shelters,” said Dr. Richard Stanwick, Chief Medical Officer for Island Health. “These individuals need to know they are at significant risk of overdose, especially if they use alone.”

Front-line staff and community service providers have also been warned of the spate of overdose deaths in recent days so they can bolster their response capacity.

Stanwick warned that street drugs have become more potent and dangerous “than they ever have been before.”

Island Health is asking users to avoid using alone, try only a small amount of new drugs first, stagger use with friends, avoid using more than one drug at a time and to always have a naloxone kit nearby.

The spike in deaths comes a week after Island Health identified potential locations for publicly-accessible supervised drug consumption sites in Victoria.

The BC Coroner Service said last month that the number of illicit drug-related deaths in 2016 to that point had already eclipsed last year’s total.

From Jan. 1 through Sept. 30 of this year, 555 people died from drug overdoses – compared to 508 deaths for all of 2015.

Fentanyl was a “major contributor” to the high number of deaths this year, according to the BC Coroners Service. More than 300 of the overdose deaths involved the potent narcotic – more than triple the number of fentanyl-detected deaths for the same period in 2015.