Emergency services were called to a home on Mayday Road shortly after 11am following reports of a house fire.

Riverina Police District superintendent Bob Noble said first responders forced entry into the house, which was well alight at that point, to retrieve the two three-year-old twin girls.

However, despite their best efforts, he said the twins could not be revived.

The mother and a five-year-old child were outside of the home at the time of the fire.

"The first responders made a great effort to get into the home, but unfortunately it wasn't quite enough," Superintendent Noble said.

"It is a particularly horrific incident, the lives of two young girls having been lost and family members and so forth are quite distraught and rightly so.

"These were two little twin girls and it is devastatingly sad to see two young lives snuffed out like that."

Superintendent Noble said a crime scene had been established, which was standard practice following an incident that resulted in a death.

He said the cause of the fire was yet to be determined.

Resident Col Anderson said he saw the smoke from his house on Batlow Avenue when he called triple-0.

Mr Anderson said an ambulance was there within 10 minutes, followed by fire trucks, police cars and more fire trucks.

"I hear a kid going off his tree, his parents screaming ... apparently it was the parents trying to get into the house because it was locked," he said.

"It was not something I wanted to see ... I've been sitting here mulling about it. It's just something you don't want to see, you don't want to know about."

Snowy Valleys deputy mayor John Larter said his thoughts and prayers were with all those affected by the incident because it was "a tragic situation for all involved".

"The families, friends and all the emergency services workers who have to deal with these dreadful scenarios - it not a good time on the back of the bushfires and the COVID-19 situation," he said.

Councillor Margaret Isselmann said the young couple, who are well-known in the community, have her "deepest sympathies". She said it was "such a sad loss".

Anyone with information about this incident is urged to contact Crime Stoppers on 1800 333 000 or via its website.