It is important to foremost stay focused and calm that will help you better protect the cats. If you believe cats are being threatened with harm, learn how to proceed at alleycat.org/community-cat-care/stop-violent-threats-against-cats/.
If you believe cats were already poisoned or injured, find next steps at alleycat.org/community-cat-care/if-cats-you-care-for-have-been-harmed-or-killed/.
Learn how to prevent poisoning, or how to proceed if a cat has been poisoned, at alleycat.org/Poison.