TOKYO, Feb 1 (Reuters) - Japanese government bond (JGB) yields rose, with the 20-year yield hitting a two-year high, after the Bank of Japan indicated it will trim the purchase of short-term and medium-term bonds in its operations this month.

The BOJ reduced the target size of its buying in the one- to three-year segment of the market as well as three- to five-year maturities.

The market is also wary ahead of the auctions for 10- and 30-year bonds scheduled this week.

The 20-year JGB yield rose one basis point to 0.465%, a highest level since January 2019.

Benchmark 10-year JGB futures fell 0.05 point to 151.77, however, the benchmark 10-year JGB yield rose 0.5 basis point to 0.055%.

The 30-year JGB yield rose one basis point to 0.665%.

The two-year JGB yield rose 0.5 basis point to minus 0.125%. The five-year yield rose 0.5 basis point to minus 0.110%.

The 40-year JGB yield rose 0.5 basis point to 0.710%. (Reporting by Tokyo markets team; editing by Uttaresh.V)