Firefighters responded to a house fire in Sydney’s south-west this morning, fearing residents could be trapped.

Six fire trucks were called to the scene at Greenacre after receiving numerous triple zero calls about a house fire on Roberts Road.

Flames were engulfing the home and there was some concerns people could be trapped.

Acting Fire Superintendent Greg Wright says two residents inside managed to get out, and were checked over by paramedics.

Detectives are now on the scene assessing the cause of the fire.

Emergency crews shut down a stretch of Robertson Road in Greenacre to battle a house fire. The occupants escaped uninjured but it made for a frightening wake up call for them and the neighbours. @10NewsFirstSyd pic.twitter.com/KRaDAJkD4n

— Amber Cunneen (@ambercunneen) June 5, 2019

It is one of several overnight blazes across the city.

Three people escaped a fire at Merrylands overnight which destroyed a home.

At Lethbridge Park in Western Sydney, firefighters had to rescue six people from a unit block after a blaze broke out in a stairwell.

And about 40 firefighters have tackled a fierce blaze in a factory at Strathfield South.