According to a 1999 census, about 65% of the population were Kyrgyz, about 14% were Uzbeks, 13% were Russians, 1% Dungan (ethnic Chinese Muslims), 1% Uighur, 1% Tatar, and0.4% German. About 420,000 ethnic Kyrgyz reside elsewhere in the former Soviet Union and 170,000 in China. Kyrgyz speak a Turkic language and most are Sunni Muslims. There are major ethnic and clan-based cleavages, including north-south clan and regional tensions that threaten fragmentation. According to some reports, 10% or more of Russians left Kyrgyzstan during 1991 because of ethnic tensions. Ethnic Germans, deported to Kyrgyzstan by Stalin during World War II, are also leaving Kyrgyzstan. In June 1990, in the Osh region on the eastern edge of the fertile Fergana Valley, a major ethnic conflict broke out between Kyrgyz and Uzbek inhabitants over land distribution. Approximately 250 people died in what has been termed "the most explosive region of Central Asia," because of its mixed population of Uzbeks and Kyrgyz, poverty, and high unemployment. Periodic clashes also occur between Kyrgyz and Tajiks along the border with Tajikistan over water resources. Beefed-up Kyrgyz security forces were placed in Osh and Alais regions in early 1993 to prevent spillover from fighting going on between Tajik ex-communists and oppositionists in the mountains of northern Tajikistan and to halt the inflow of Tajik refugees.