36 mortar shells
These appear to be mortar shells left over from the Iran-Iraq war, which means they are at least 16 years old, and probably older. Blister agents have a shelf life of about 5 years, so even if they were gas shells it would be much ado about nothing. I suspect there are a number of caches of old obsolete weapons such as these all over Iraq. Given the pathetic state of Iraq's military infrastructure after the first Gulf War it wouldn't surprise that a number of these were long since buried, undocumented and forgotten.