Pair jump from burning Bankstown unit

One woman is confirmed dead and another seriously injured after jumping from a burning apartment complex, in Sydney's south west.

An upper floor of the seven-level Bankstown building erupted in flames at 2.48pm on Thursday, trapping dozens of residents inside.

Police officers say one of the women landed on a ledge on the first floor, and a 28-year-old woman has been rushed to Liverpool Hospital with minor burns and a suspected broken leg, according to the ABC.

Another eight people were reportedly taken to hospital and around 40 people were treated at the scene for smoke inhalation.

The entire complex was evacuated, and police are now investigating reports that the fire was proceeded by an explosion.

Very early reports are suggesting that some sort of drug lab may have been inside the building, and fearing detection, the operators of this illegal operation took things into their own hands in order to destroy evidence, but such reports are yet to be confirmed.

Police are yet to rule out suspicious circumstances.