The Mayor of Montreal pledged Monday to tighten regulations on Airbnb as she continues the search for six missing people after a fire engulfed a building housing Airbnb accommodations in a historic area of ​​the city where Airbnb accommodations are forbidden.

Firefighters initially thought someone was missing in last Thursday’s blaze in the eastern Canadian town. However, reports of illegal Airbnb units in the more than 130-year-old building have surfaced and authorities over the weekend updated the number of missing people to seven, including some from the United States.

Montreal police say they pulled a woman’s body from the rubble on Sunday afternoon.

Montreal Police Inspector David Shane said the six people still missing are from Quebec, Ontario and the United States, adding that investigators have already contacted their families. Thursday’s fire also injured nine people, two of whom were hospitalized.

The cause of the fire is under investigation.

Montreal Mayor Valérie Plante said the building contained illegal Airbnb units and an architect’s office. Plante added that Airbnb should have required unit owners to provide a permit number from the government of the province of Quebec.

“What happened here is a real tragedy,” Plante said. “Obviously, we wouldn’t be in this situation if we were dealing with a company that took its responsibilities seriously and told these landlords that if they don’t have a certificate, they can’t rent their accommodation. And it would force those who want to act illegally and not pay taxes not to shirk their responsibilities.”

Plante said he would work with the Quebec provincial government to tighten regulations on short-term rentals.

Firefighters said several apartments in the building were being used as Airbnb rental units, and police said they don’t know how many of the missing tourists were tourists. San Francisco-based Airbnb is “washing its hands” of the problem of illegal rentals in Quebec cities, Plante added.

Nathan Rotman, Airbnb’s regional policy director for Canada, said in an emailed statement: “We are cooperating with authorities in their investigation. We are also in communication with the town hall.