Stock markets fell across Asia. At the domestic bourses, the Sensex at the Bombay Stock Exchange ruled extremely weak, and had tumbled 522 points, to 25,761 in afternoon trade, a short while ago. Earlier in the morning, the Sensex had lost 299 points. Selling was seen across-the-board. Similarly, the Nifty at the National Stock Exchange had plunged 163 points, to 7,808 a short while ago.The Chinese market had slipped 1.3 percent, after data showed that country's manufacturing sector contracted significantly in August. Other key markets in Japan, Hong Kong, South Korea and Singapore had lost between 0.4 percent and 3.8 percent.