The Sensex at the Bombay Stock Exchange declined 33 points, or 0.2 per cent, to 19,284 in early trade, today, as investors booked profits ahead of the Reserve Bank's mid-quarter monetary policy review, tomorrow. Later, the Sensex remained weak, and stood 49 points, or 0.3 per cent in the red, at 19,268 in afternoon deals, a short while ago.Key stock indices in Hong Kong, Indonesia, Taiwan, Singapore and South Korea had fallen between 0.1 percent and 0.8 percent today.