Falling for the fifth straight session, the Sensex at the Bombay Stock Exchange declined 148 points, or 0.8 percent, to close at an over two-week low of 18,471, today, as weak global stock markets weighed on sentiment. The Sensex had lost over 280 points in the previous four trading sessions. The Nifty at the National Stock Exchange fell 36 points, or 0.6 percent, to 5,631. Stock markets in China, Hong Kong, South Korea and Singapore declined between 1 percent and 1.5 percent, on persistent worries about the US fiscal problem.