In late February and March 1988 Armenia (predominantly Christian) and neighboring Azerbaijan (mostly Shiite Muslim) began violently pressing their territorial claims to Nagorno-Karabakh, a mostly mountainous agricultural region located within Azerbaijan's boundaries but home mainly to Armenians. Bloody ethnic clashes also occurred over control of Nakhichevan, a smaller area bordering Iran and separated from Azerbaijan by a strip of Armenian territory. Situated in the southwestern part of the Soviet Union, between the Black and Caspian Seas, the two republics of Armenia and Azerbaijan soon turned their ethnic conflict into a popular revolt against Soviet rule. When Azerbaijani militants called for the republic's reunification with part of northern Iran, Moscow declared a state of emergency and, in late January 1990, sent 11,000 troops to help the 6,000 Soviet soldiers already in Azerbaijan; they invaded the republic's capital city of Baku. Thus the conflict, which had begun with skirmishes with hunting rifles, escalated to battles with missiles, tanks, and heavy artillery. In the late summer of 1991 Azerbaijan and then Armenia declared independence, but they did not become real independent states until the Soviet Union dissolved on December 26, 1991. Efforts to resolve the war by the United Nations, Iran, and others failed in 1991 and1992. Fighting resumed, with both sides blaming the other for truce violations. In May 1994 Russia mediated a ceasefire, with Armenian soldiers in control of Nagorno-Karabakh. Sporadic fight has occurred since, and no progress has been made toward a political settlement to end the conflict.