Sayyiduna Sa'b bin Jaththamah (may Allah be pleased with him) said: We said: O Messenger of Allah, we attack one of the houses of the polytheists in the morning, and children are trampled under the hooves of the horses without our knowing (so what is the ruling)? He (peace and blessings be upon him) said: "They are also of them."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7425