Six mice and four birds have also been poisoned in the Pentland Avenue and Chiltern Road area in a week.

RSPCA Insp Corina Stables said the animals had died "horrific deaths" and added that it was an "extremely worrying" situation.

"We believe someone may be laying poison indiscriminately," she said. Vets confirmed the cats were poisoned.

She added: "We would urge people to remain vigilant for the foreseeable future and keep an eye out for open cans of food which may be contaminated."

Owners are being advised to watch out for slug pellets scattered in the street.

Tell-tale signs of poisoning include vomiting or convulsions.