Young sisters dead in Melbourne

Two young sisters are dead and a man known to them is in custody in an Easter Sunday tragedy in Melbourne.

The girls, both aged under 10, were found dead at a house in Watsonia, and a man known to them was arrested at the scene on Sunday afternoon, police said.

He is being interviewed by detectives.

Police have yet to reveal how the children died or give details of any injuries.

A number of family members were at the home at the time the incident unfolded.

Assistant Commissioner Andrew Crisp said the tragedy had touched many.

"This is a tragic set of circumstances that has impacted on the family, and there were a number of family members here at the time," he said at the scene.

"It's naturally impacted on friends, neighbours and also on members of the fire brigade, the ambulance services and members of Victoria Police who have attended the scene today."

Police were called to the Longmuir Road home about 2.40pm (AEST).

Ambulance Victoria said paramedics treated two people in a critical condition there for some time, but could not be save them.

A neighbour said the incident was hard to comprehend.

"(I feel) sick to the stomach," he said.

"It's really hard to believe this could happen in a quiet little suburban street."