An elderly woman is in serious condition in hospital and a man is in custody after a stabbing in a King West apartment building, Toronto police say.

Officers were called to a building at King and Bathurst streets at about 8 a.m. for a report of a man with a knife in a hallway.

They arrived to find a woman who was stabbed several times in one extremity.

Paramedics said she suffered seven or eight wounds and was taken to a trauma centre in serious but non-life-threatening condition.

A male suspect was arrested at the scene.