Sunan Abu Dawood, Chapter: Prayer (Kitab Al-Salat)

Abu Salih al-Ghifari reported: Ali (once) passed by Babylon during his travels. The mu'adhdhin (the person who calls for prayer) came to him to call for the afternoon prayer. When he passed by that place, he commanded to announce for the prayer. After finishing the prayer he said: My affectionate friend (i.e. the Prophet) prohibited me to say prayer in the graveyard. He also forbade me to offer prayer in Babylon because it is accursed.