Write SQL query to solve given problem: List all the ID of the images that have an attribute class of "horse".. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.IMG_ID FROM ATT_CLASSES AS T1 INNER JOIN IMG_OBJ_ATT AS T2 ON T1.ATT_CLASS_ID = T2.ATT_CLASS_ID WHERE T1.ATT_CLASS = 'horse'