Police said Nicholas Gibson, age about 3 months, and Anna Gibson, 2 years, were found in a bathtub alone in the home in Winnipeg's Westwood neighborhood about 8 a.m. CDT, and were rushed to a hospital where they were pronounced dead, sources told QMI Agency.
The Canadian Broadcasting Corp. reported police had spoken to the father and were searching for the children's mother, Lisa Gibson, 32.
QMI Agency said police had not declared the deaths a double homicide but the news service's sources said investigators were handling the matter as if it were.
Police said Lisa Gibson was the last person to see the children and was a "person of interest," CTV Winnipeg reported. Neighbors said the children were found in a bathtub, though police had not confirmed how the children died, the network reported.
A fire official told the CBC Lisa Gibson was believed to be wearing pajama pants and was distraught.
The Winnipeg news website ChrisD.ca reported authorities were searching the nearby Assiniboine River and vicinity for the missing mother. She is described as 5-foot-5 with short, light blond/red hair and a slim build.