Quebec City police said an 83-year-old man assaulted a woman in a building on Forest Street in the Sainte-Foy neighbourhood on Monday morning.
According to authorities, the man may have attacked her with an axe.
Const. Pierre Poirier said the woman has injuries on an arm and on her head. But he said she is conscious and in stable condition at the hospital.
"We can't make the connection right now between these two persons," he said. "It will be at the end of the investigation, we will be able to say what is the relation between them."
Police said the man also sustained injuries to his upper body. Poirier said he was treated at the hospital.
He is now in police custody and could appear in court Tuesday morning.