Ottawa is reeling from its third murder in less than a week after a 21-year-old university student was stabbed to death in her apartment in an upscale neighbourhood.

The victim, identified as K'Leigh Cundall, was on the phone with her boyfriend when someone knocked on the door of her basement apartment in New Edinburgh. She put the phone down to answer it and was attacked by a knife-wielding assailant, police said.

Cundall's boyfriend heard her screams over the phone and immediately hung up to call 911, said Ottawa police Sgt. Ron Bos. Neighbours also rushed to her aid.

Police found the University of Ottawa student with about 20 stab wounds in her chest, neck and back. She was later pronounced dead at hospital.

Police believe Cundall, who was from a small town outside of Toronto, knew her attacker. Charges are pending against a 21-year-old man who was at the scene when police arrived.

It's the third murder this week in Canada's capital, which has had 11 homicides this year. That's one more than the city recorded in all of 2004.

On Tuesday, two men were shot and killed at a karaoke bar in Chinatown.

Police identified the two victims as Tailang Liu and Linhai Tian, both 20. They were foreign students from the Chinese border city of Shenzhen.

The two men were shot several times after what appeared to be an argument at a cafe. One man died instantly. The other died in hospital.

There have been no arrests in the two shootings.

The investigation is complicated by a lack of witnesses because many people in the community feared the shooting was gang-related, something police say isn't likely.

Ottawa Police Sgt. Syd Gravel said it's difficult to gain the trust of people from countries where there is a deep distrust of police. Next week, police will hold a series of public meetings in the community to try to allay fears.