Iraq said the Islamic State extremist group has taken control of a vast former chemical weapons facility northwest of Baghdad, where 2,500 chemical rockets filled with the deadly nerve agent sarin or their remnants were stored along with other chemical warfare agents. Iraq's U.N. ambassador, Mohamed Ali Alhakim, said in a letter to U.N. Secretary-General Ban Ki-moon in a letter circulated Tuesday that "armed terrorist groups" entered the Muthanna site on June 11, detained officers and soldiers from the protection force guarding the facilities and seized their weapons. The following morning, the project manager spotted the looting of some equipment...