Calgary police have a suspect in custody after a stabbing at a medical centre left one dead and put another in hospital.

Police said they were called to the Perpetual Wellness Chinese Medical Centre in the Central Landmark building around 2:35 p.m. and found a deceased man and a man and woman with non-life-threatening injuries.

The woman was taken to hospital and the man was treated at the scene and then taken into custody, said police.

Police stand outside the Perpetual Wellness Chinese Medical Centre where one person was killed and another injured in a stabbing. (Jennifer Lee/CBC)

Insp. Dean Lagrange with the Calgary police said the incident was "domestic in nature" and that all three individuals knew each other.

"I believe that the target was the deceased individual," he said.

Lagrange said the suspect was calm and co-operative when police arrived and did not put up a struggle when he was taken into custody.

He was not sure why the suspect remained at the scene, nor would he speculate on a motive, but said, "You can draw your own conclusions on it being domestic in nature."

Witness accounts

Maggie Law, who owns the Misato Spa in the building, said she walked by the clinic about five minutes before the stabbings took place.

"After that I hear something happened, and then I just run there to take a look. And then I saw just two people lying down on the floor, and then I just heard people: 'Grab some more towels.'"

Emma Wong, the manager at Essential Eyewear on the main floor of the building, said she has seen "nothing like this" before.

"In the past we've had gunshots, we've had knife fights, but never a fatality like this," she said.

Police have closed the southbound lanes of Centre Street North between 16th Avenue and 13th Avenue.