Two people are believed missing and seven police officers are in hospital after an explosion and fire that has gutted a supermarket and residential premises in Sydney’s west.

Neighbours say the explosion in Wentworthville happened just after 4.15am (AEDT) on Tuesday and was heard and felt from streets away.

Local woman Colleen says she felt her house shake even though she lives several streets away.

“There was a loud explosion and I woke up to my house shaking and then all this popping noise and then all the people screaming,” she told Fairfax Radio.

“It was that loud that I heard it from streets away.”

The building on Station Street has completely collapsed as a result of the blaze.

A Fire and Rescue NSW spokesman at the scene told AAP two people are reported missing inside the building.

Two other people injured in the blaze managed to escape and have been taken to hospital.

Seven police officers are also in hospital suffering smoke inhalation.

Police have declared the area a crime scene and are treating the blaze as suspicious.

It’s understood the two-storey building comprised of residential units on top of a commercial premises, possibly a supermarket.

The Fire and Rescue spokesman says emergency workers are using thermal imaging cameras to “try to get in there and work out how many people might be in there”.

It’s not yet known what sparked the fire.

Police say it’s also not known if an explosion at the building caused or was a consequence of the fire.

They say the two men injured in the fire are in a stable condition at Westmead Hospital, and are being treated for burns.

AAP