Assistant Commissioner Rhonda Blackmore speaks during a press conference at RCMP "F" Division Headquarters in Regina, Saskatchewan, on Sunday. AP
The killings in the remote James Smith Cree Nation Indigenous community and the town of Weldon in Saskatchewan province in western Canada are among the deadliest incidents of mass violence to ever hit the nation.
Police have been scouring Saskatchewan and two neighboring provinces for the men, identified as Myles and Damien Sanderson, aged 30 and 31 respectively, since early Sunday.
On Monday afternoon, Damien Sanderson's body was "located outdoors in a heavily grassed area in proximity to a house that was being examined" by authorities in the James Smith Cree Nation, federal police Assistant Commissioner Rhonda Blackmore told a news conference.
He had "visible injuries" that were not self-inflicted, she said.
"We can't say for sure how Damien came to be deceased," Blackmore said, adding that he "could potentially" have been killed by his brother Myles who remains at large and is "strongly believed" to have also sustained injuries.
The manhunt for Myles Sanderson continues, with border officials alerted to the possibility he may try to sneak into the United States.
Evan Bray, police chief of provincial capital Regina, said authorities were still operating under the assumption that he was hiding out in the city -- 300 kilometers (185 miles) from the site of the attack -- after suspected sightings in the area.
He urged residents "to be very aware of your surroundings and report anything that's unusual or any information that you might have" in a video posted to Twitter Monday evening, adding that the search would continue through the night.
Earlier, federal police announced that murder, attempted murder and burglary charges were laid against the pair, adding that further charges are anticipated as the investigation progresses.
Myles Sanderson has also been wanted since May for breaching parole, after reportedly serving part of a five-year sentence for assault and robbery.