Nearly 500 people may have been killed by record-breaking temperatures in Canada’s westernmost province, as officials warn the grim toll from “heat dome” could rise again as more deaths are reported.

On Friday, British Columbia’s chief coroner said that 719 “sudden and unexpected deaths” had been reported over the past week – triple the number during a similar period in a typical year.

“We are releasing this information as it is believed likely the extreme weather BC has experienced in the past week is a significant contributing factor to the increased number of deaths,” the chief coroner, Lisa Lapointe, said in a statement.

The coroner’s office said it would typically expect close to 230 deaths in a similar period.