Lethbridge police are investigating what's now being called a triple homicide in the southern Alberta city.

A concerned neighbour called police at about 2:30 a.m. MT to check on an address in the 200 block of McGill Boulevard West.

Lethbridge triple homicide

Police were on the scene of a triple homicide in Lethbridge on Tuesday. (CBC)

Officers found three adults — a woman, 24, and two men, aged 18 and 27 — dead inside the townhouse in a violent crime scene, said Deputy Chief Colin Catonio.

Their identities have not been released while police notify next of kin.

"It's our opinion that this was targeted," he said, adding that police do not believe the public is at risk.

Catonio said police have been called to the same address on previous occasions. It's too early to say whether the incident is drug related, he said. 

Investigators are still at the scene working to confirm the identity of the victims.