In the late 1970s, Iran hired the U.S. companies Westinghouse and Hughes Aircraft to build a missile assembly and repair plant in Shiraz in cooperation with Iran Electronics Industry, but the project was halted after the 1979 revolution. [1] Since then, the plant has been reported as one of several alleged missile production sites in Iran. The Shiraz plant is allegedly producing fuel and components for Shahab-1/Scud-B missiles and conducting research and development. [2]

Sources:
[1] John P. Miglietta, American Alliance Policy in the Middle East 1945 - 1992: Iran, Israel and Saudi-Arabia, (Lanham: Lexington Books, 2002), p. 95; Will Dossel, "Ballistic Missile Defense," in Securing Freedom in the Global Commons, ed. Scott Jasper (Stanford, CA: Stanford University Press, 2010), pp. 115-130.
[2] Yonah Alexander and Milton M. Hoenig, The New Iranian Leadership (London: Praeger Security International, 2008), p. 179; Andrei Frolov, "Iran's Delivery Systems Capabilities," Security Index No. 2 (82), Vol. 13, Summer/Fall 2007, PIR Center, p. 31.