Indian government bonds built on a two-day rally early on Thursday on bets the Reserve Bank of India was buying in the secondary market, with added support from firmer U.S. Treasuries. The benchmark 10-year 6.48% 2035 bond yield was at 6.6416% by 10:30 a.m. IST, after ending at 6.6536% on Wednesday. The yield has fallen about 3 basis points over two sessions. Speculation picked up after clearinghouse data showed investors classified as "others", including insurers, pension funds, corporates and the RBI, bought a net of 65.7 billion rupees worth of bonds on Tuesday and Wednesday. RBI purchase data for the week ended January 16 is due on Friday.