Man charged over Sydney nursing home fire

The registered nurse charged with four counts of murder after a fatal fire at a nursing home in Sydney's west is believed to have worked there for only a short time, police say.

Police said it was expected to take some time to piece together what happened after two fires are believed to have broken out in separate wings of the Quakers Hill nursing home in the early hours of Friday morning.

Three elderly residents died in the blaze, while another died late Friday afternoon in hospital.