In late July 1993, the United States alleged that a Chinese ship was carrying chemical weapon materials to Abbas Harbor, Iran, citing a ship's manifest obtained by its Central Intelligence Agency. The United States requested that the Yinhe turn back to China in order to unload its alleged cargo, but China refused after conducting an investigation and determining that no chemical weapons precursors were present on the ship.[3] At this time, the Yinhe had already departed China and was on its way to Kuwait.