A 70-year-old man was critically injured late Sunday when he was stabbed in the neck during a fight with a fellow patient at a mental health facility in The Bronx, police sources said.

The victim was attacked by the knife-wielding man inside the building on Hughes Avenue near East 174th Street in Tremont at around 11:40 p.m., sources said.

The man suffered a stab wound to the neck and was rushed to St. Barnabas Hospital in critical condition.

Police caught a 46-year-old suspect at the scene a short time later. Charges against him are pending.

Both of the men are residents at the Urban Pathways Mental Health Center, police said.