Man critically injured in Melbourne fire

A man is in hospital under police guard after a house fire in Melbourne's north.

Emergency services were called to the Rhodes Parade unit in Pascoe Vale about 4.50am on Tuesday, following reports a man had smashed a window.

Police then received reports there was a fire at the property and a man was seriously injured.

The man was taken to hospital with critical injuries. He is under police guard.

A woman, believed to be known to the man, escaped injury.

Detectives are investigating the fire, which they believe was suspicious.