A man is in critical condition following a serious assault in River Heights early Monday.

Police were interviewing witnesses in connection with the incident which happened just after 2 a.m.

A man in his 20s was found at a home in the 100 block of Lindsay Street suffering from serious upper body injuries.

Police said there was a family gathering at the residence. Investigators remained at the scene later Monday morning and a home at 169 Lindsay was taped-off. Medical packaging was strewn on the front lawn.

Neighbours in the normally quiet neighbhourhood said they were shocked to be awakened in the middle of the night to the sound of police and emergency sirens.

The Major Crimes Unit is investigating.

Police are expected to release more information later today.