Bank of Japan to conduct unscheduled bond-buying operation.

The Bank of Japan announced an unscheduled bond operation on Tuesday, as it sought to slow a rise in Japanese government bond (JGB) yields that had brought them to fresh decade highs.

Japan's central bank offered to buy 300 billion yen ($2 billion) in bonds with maturities of five to 10 years and 100 billion yen worth with maturities of 10-25 years from Wednesday.

That was in addition to its daily offer to buy an unlimited amount of JGBs at a fixed rate of 1 percent.

Bank of Japan intervenes as 10-year JGB yield hits fresh decade peak

Following the BOJ's announcement, the 10-year JGB yield declined 0.5 basis point to 0.855 percent, earlier trading unchanged from Monday's closing level of 0.86 percent, which was the highest since July 2013.

Japanese yields have been...