A 64-year-old man is in hospital with critical injuries after a fight with his neighbour last night.
The incident happened at a home on Latour Street in Longueuil's Saint-Hubert borough.
Police said the fight started as an argument between neighbours, and escalated to a physical altercation.
A Longueuil police spokeswoman said the man's injuries are considered to be life-threatening.
Police are questioning a 29-year-old-man arrested at the scene in connection with the incident.