Police are investigating an assault in Waterloo early Sunday that left a man with life-threatening injuries.

Waterloo Regional Police responded to a call for help at a home at Allen Street East in Waterloo at around 5:30 a.m.

When officers arrived, they found a 44-year-old man with severe head injuries. The man was rushed to hospital, and is now on life support, Insp. Kevin Thaler told CBC News.

Two men have been arrested and homicide investigators are now probing the case. A 46-year-old man and a 19-year-old man are "being charged with aggravated assault at this time," said Thaler.

Police are asking anyone with information about the assault to call police's north division detectives at 519-653-7700 ext.. 6399 or Crime Stoppers at 1-800-222-8477.