Asian stock markets fell Monday, AP reported. Hang Seng in Hong Kong tumbled 3.3% to 18,879.20 and the Nikkei 225 in Tokyo shed 1.4% to 26,945.67. The Shanghai Composite Index lost 0.5% to 3,234.91. The Kospi in Seoul retreated 0.7% to 2,379.20 and Sydney's S&P-ASX 200 lost 1.4% to 6,898.50. India's Sensex lost 1.4% to 57,177.69. In energy markets, benchmark US crude plunged $2.11 to $64.63 per barrel in electronic trading on the New York Mercantile Exchange. Brent crude, the price basis for international oil, lost $2.29 to $70.68 per barrel in London. The dollar declined to 131.17 yen from Friday's 131.67 yen. The euro retreated to $1.0646 from $1.0681.