The Sensex at the Bombay Stock Exchange closed with a loss of 61 points, or 0.3 per cent, at 17,971, as weak global markets offset data showing impressive first quarter GDP growth, today. The Nifty at the National Stock Exchange lost 13 points, or 0.2 percent, to 5,402. Stock markets in Japan, China, Hong Kong, South Korea and Singapore lost between 0.2 percent and 3.5 percent.