Four cars have been torched in a shocking arson attack on a home where 11 people, including an infant, were sleeping.

The cars and a garage were set alight on Burnell St in Russell Lea, in Sydney’s inner west, at about 2.30am on Thursday.

The 11 people inside the home, ranging in age from just two weeks old to 71-years-old, escaped the home and were not injured.

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The same home was attacked in a similar incident in 2013.

Fire and Rescue NSW attended and extinguished the fire.

“We initially sent three fire trucks with 12 firefighters,” Fire and Rescue NSW Superintendent Adam Dewberry said.

“When our first trucks arrived ... there were a couple of cars on fire in the front of this garage.

“It was threatening to spread into the garage. Firefighters were able to cut that off, fortunately.

“It took about 20 minutes to extinguish.

“Two cars were destroyed by the fire (and) another two have suffered some heat damage.

“The garage has also suffered some heat damage.

“Firefighters also entered the structure to make sure that there was no fire spread or any toxic smoke that had travelled into the home.”

NSW Police are investigating the fire, which is being treated as suspicious.

“Words were written on (two of) those vehicles to suggest that the persons responsible have some association with the occupants of the home,” NSW Police Superintendent Christine McDonald said.

“However, that is something we are currently working through.”

The words were “offensive” but not politically or racially motivated, McDonald said.

The residence was targeted in a similar incident in 2013, and NSW Police will investigate whether the two are linked, McDonald said.

Seven cars were destroyed in the 2013 fire.

“(The theory of) a decade-long feud is one that we will look into.

“I mean, it’s a hell of a long time to hold a grudge, but we do know that people do hold grudges for a long time.

“But that is something that will be part of our inquiries.”

An accelerant was used to start the fire, McDonald confirmed.

CCTV has been obtained of two people approaching the vehicles just before the fire.

Residents in the area have been asked to check their security cameras for footage from around the time of the fire.

‘We’re lucky that no one is dead’

Emergency services highlighted the immense danger of the fire.

“All fires are dangerous, car fires in particular,” Dewberry said.

“Live electricity can come down and that electricity can actually spread across a moist ground which we get at this time of year as well,” he said, adding that overheard wires were damaged.

“But these fires can spread into your home, spread quickly and destroy homes within minutes as well.”

McDonald called the fires “so irresponsible” and “so risky”, noting there was an infant inside the home.

“The risk of someone being injured was obviously extremely high.

“I don’t think offenders that light vehicle fires actually think about the consequences, but in this scenario we’re lucky no one was injured.

“We’re lucky that no one is dead.

“I implore anyone who wants to go out and light a vehicle fire: have a think before you do it.”