It wouldn’t bother me so much if these were simply Hindus who, sitting or kneeling in the pews, worshipped our Lord and Lady as a goddess. At least I would think, “Oh well, maybe this will bring them closer to the Truth.”
But the fact that their incantations were loud and public, that bothers me.
I know that, in India, it’s always been common, since the days of Saint Thomas, for Hindus to visit Christian shrines and pray at them. This is because Hindus believe that all the world’s deities are but manifestations of a single god, or a single principle: Brahman. Others see all the god-images, Hindu and non-Hindu, as symbols of one or anothe aspect of the All (Brahman).
In any event, I agree that what happened should not have been allowed to. If Hindus want to worship privately at Fatima, that’s one thing. They should keep their public ceremonies out.