TOKYO, Jan 21 (Reuters) - Japanese government bond yields fell on Thursday after the Bank of Japan kept monetary policy steady but warned of escalating risks to the economic outlook as new state of emergency measures rolled out this month hit consumption. The BOJ maintained its policy targets under yield curve control (YCC) – minus 0.1% for short-term rates and around 0% for 10-year bond yields – at its policy meeting. The 10-year JGB yield fell 0.5 basis point to 0.030%, while the 20-year JGB yield fell 0.5 basis point to 0.440%. The 30-year JGB yield fell 0.5 basis point to 0.655% and the two-year JGB yield fell 0.5 basis point to minus 0.140%. The five-year yield fell 0.5 basis point to minus 0.120%. (Reporting by Tokyo markets team; Editing by Shailesh Kuber)