What is the ruling on praying in a mosque that contains a room with two graves, and this room is opened to retrieve some supplies?

It is not permissible to pray in mosques that contain graves, and these graves must be removed by transferring their remains to public cemeteries. The Prophet, peace and blessings be upon him, forbade this and cursed the Jews and Christians for doing so. He also warned against taking graves as places of worship (masajid), and described those who do so as the worst of creation in the sight of Allah. Indeed, praying at a grave or building a mosque over it is considered taking it as a mosque, which could lead to major shirk (polytheism). If a mosque is built over old graves, then the mosque must be demolished because it is the innovation.