Sahih Muslim
The Book on Salutations and Greetings (Kitab As-Salam)
Book Number: 026 / Hadith Number: 5559
Abu Sa'id Khudri reported Allah's Messenger having said: There is a group of jinns in Medina who accepted Islam, so he who would see anything from these occupants should warn him three times; and if he appears after that, he should kill him for he is a satan.