U.S. stocks followed world markets lower Monday as investors worried about increased tensions between Russia and Ukraine. In international economic news, investors were cautious following news that Russia has moved forward with military intervention in Ukraine. Ukraine's new leaders have accused Russia of declaring war. All the major European stock markets closed sharply lower, with Germany's Dax dropping more than 3 percent. France's CAC 40 fell more than 2 percent and London's FTSE 100 declined about 1.5 percent. The Ukraine fears hit most Asian stock markets as well. Hong Kong's Hang Seng index closed 1.5 percent lower and Tokyo's Nikkei dropped 1.3 percent. Stocks in Shanghai and Shenzhen bucked the trend and moved higher. Stocks in Russia fell the most. The Micex index tanked almost 11 percent, while the Market Vectors Russia ETF was down 6 percent. Shares of energy giant Gazpro dropped more than 10 percent, and Russian search engine Yandex was down about 14 percent. The dollar was unchanged against the pound, gained ground against the yen, but lost ground versus the euro. Light sweet crude oil for April delivery added $2.33 to $104.92 a barrel on the New York Mercantile Exchange. Gold futures climbed $28.70 to $1,350.30 an ounce. The Dow Jones industrial average dropped 153.68, or 0.94 percent, to 16,168.03. The broader Standard & Poor's 500 index lost 13.72, or 0.74 percent, to 1,845.73. The technology-heavy Nasdaq composite index fell 30.82, or 0.72 percent, to 4,277.30.