How can one pray over the deceased if the funerals of Muslims and non-Muslims are mixed during disasters, making them indistinguishable?

It is not permissible to pray over a disbeliever. If the bodies of Muslims and disbelievers are mixed and cannot be distinguished, the Shafi'is, Malikis, and Hanbalis agree that it is permissible to pray over all the bodies with the intention of performing the funeral prayer only for the Muslims, while dedicating the supplication specifically for the Muslims among them. The Hanafis, however, hold that if the Muslims are more numerous, one should pray over them with the intention for the Muslims, otherwise not. As for the manner of prayer, it is by arranging them in front of the worshipper and praying over them all at once with the intention for the Muslims among them, or by praying over each body individually with the intention for the Muslim among them.