The Australian Broadcasting Corporation said up to nine died while Sky News cited police as saying "fewer than 10" with others rushed to hospital suffering smoke inhalation or burns.
"There are fatalities but we are not going into that at the moment," a police spokesman told AFP.
"There are a number of processes that we have to go into in terms of identification and contacting family members before we can give out that information."
Up to 90 firefighters, a large number of police and paramedics raced to the Quakers Hill Nursing Home in the early hours of the morning when an automatic fire alarm went off to find a scene they said was "chaotic and tragic".
"This has been a very, very serious fire, a tragic scene -- a lot of people injured. There have been some fatalities, there may be more," Fire and Rescue NSW Commissioner Greg Mullins told reporters.
"This is a firefighter`s worst nightmare," Mullins added.
"Crews had to literally crawl on their hands and knees into every room in the complex, reach up under the beds, searching cupboards, anywhere where someone may have crawled away.
"So it has taken quite some time because of the thick black smoke to confirm that we had all of the residents cleared."
Police added that they believe the inferno started in a bedroom and Mullins said it would have been an horrific experience for the old and frail.
"They are confused ... they are not sure what is going on," he said.
Television pictures showed dozens of elderly people lying on beds or sitting in wheelchairs outside the home, some of them being attended to by paramedics.
Around 100 people were evacuated from the building and NSW Ambulance Assistant Commissioner Mike Willis said 50 people had been transported to hospital so far.
"It was a chaotic scene that confronted us," he said.
"It`s too early to speculate on the number of people who have been taken to hospital for injuries or just for the residential care they require.
"I don`t have figures on casualties."
Homicide and arson squad detectives have been called in to investigate the cause of the blaze. (*)
Editor: Kunto Wibisono
Copyright © ANTARA 2011
