Kittens that were less than two weeks old were left to die in a box in a supermarket car park.
The five animals were found abandoned in the ASDA car park in Acle New Road, Great Yarmouth.
They were found on Monday and one was already dead when they were found.
In a post on the RSPCA East Norfolk Branch Facebook page it said they tried hard to save the others but sadly with their terrible flea infestation and being so cold and hungry they were just too weak to survive.
Debroh Cook from the RSPCA said: 'Who knows how long they had been there? At around ten days old they didn't stand a chance.
'Please neuter your cats as there is no need for this to happen with help out there from so many charities. Let's just hope the mother cat does not have another litter.'
She said RSPCA East Norfolk can help with neutering costs and can help rehome pregnant cats and their litters.
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