Six bodies have been found in a marshy area of Quebec, near Canada's border with New York state.
The Akwesasne Mohawk Police Service said they were awaiting the results of postmortem and toxicology tests to determine the cause of death.
They are still trying to identify the dead and their immigration status in Canada.
It was not immediately known if they were migrants trying to cross the border, police said on Thursday.
The bodies were found in the Tsi Snaihne area, which lies on the southern shore of St Lawrence river in Quebec, east of Akwesasne.
“The first body was located around 5pm, in a marsh area in Tsi Snaihne, Akwesasne, Quebec,” police wrote on social media. “There is no threat to the public at this time.”
Akwesasne is a Mohawk tribal territory straddling the Canadian provinces of Quebec and Ontario, and the US state of New York.
Last month, the Akwesasne Mohawk Police Service and the Saint Regis Mohawk Tribal Police reported an increase in illegal entries through their lands and waterways.
They said some migrants required hospital treatment.
In January, the force said people involved in human smuggling had attempted to use the banks of St Lawrence river.
US President Joe Biden and Canadian Prime Minister Justin Trudeau announced a plan last week to close a loophole in an immigration agreement that allows thousands of asylum-seeking migrants to move between the two countries along a back road linking New York state to Quebec.
The deal, which closes the illegal border crossing point about 105km east of Akwesasne, came into effect on Saturday.
