The first 53 are detailed in this document, courtesy of USAID.
Since the Saddam Hussein regime was overthrown in May, 270 mass graves have been reported. By mid-January, 2004, the number of confirmed sites climbed to fifty-three. Some graves hold a few dozen bodies, their arms lashed together and the bullet holes in the backs of skulls testimony to their execution. Other graves go on for hundreds of meters, densely packed with thousands of bodies.The 54th is from an e-mail sent by a friend of mine in Israel. It's so that no-one has to hear a radio broadcast like this ever again.
Thanks to TCP reader Ronnie Schreiber, here is a translation:
We all recognize that signal that we have just heard. This is a genuine alert. There is a missile attack on Israel. All Isreali residents should immediately put on their gas masks and should go into their sealed rooms and place their families in the room. The room should be sealed with rags and with adhesive tape. As is known and recognized, stop your normal activities, check on your children and put on their gas masks in the correct manner, and continue to listen to us. This is a genuine alert, a missile attack on Israel and we will have more details as they come in… To review procedures in the sealed room, do not sit near exterior walls or walls adjacent to the exterior walls. Stay near the interior walls. Don’t face the exterior walls. Sit on the floor…If you have a family check on your children, make sure you have the key to the lock so you can lock the door, and proceed to your sealed room. This message will be repeated in Russian.