Several moggies have been shot, including at least one that was killed, in the Patterdale Crescent area of Maghull.
In the latest incident, a pet cat named Mo – after Liverpool star Mo Salah – reportedly needed surgery after being shot in the face with an air gun last week.
An RSPCA spokeswoman hit out at the attacks and urged anyone with information to contact the charity.
“It is very distressing to think that people take pleasure in causing such horrific injuries to defenceless animals,” the spokeswoman told Sky News.
“These are deliberate and brutal acts of cruelty.
“Cats and wildlife are normally the animals that are more susceptible to these incidents simply because they are out in the open with no-one to protect them.
“Unfortunately, air rifle attacks are not as rare as we would like. The injuries caused by such attacks are horrific and often fatal.”
Residents told the Liverpool Echo that up to 13 cats have been targeted in attacks over the last two years, including four cats that have suffered air gun pellet wounds.
Merseyside Police said it was aware of two incidents that had been reported to the force – in November 2016 and 20 July this year.
Ian Jones, inspector of community policing, said: “It is unacceptable that cats are being attacked in this way, it is distressing for owners and extremely cruel to harm a defenceless animal.
“We have been working alongside the RSPCA and would appeal to anyone with any information to come forward and help us put a stop to this senseless behaviour.”
The Maghull attacks come after a spate of cat killings in Northampton last year, while a suspected “Croydon cat killer” has been linked to hundreds of deaths and mutilations of animals in Greater London since 2015.
The RSPCA said it received almost 1,000 calls every year about animals that have been targeted with air guns.
Anyone found guilty of deliberately using an air gun to hurt an animal can be jailed for up to six months or receive an unlimited fine.