The Bank of Japan stepped up plans for its bond-buying on Friday as Japanese government bond (JGB) yields crept higher, causing the yen and oil to drop.

On Friday, the BOJ said it would buy an unlimited number of 10-year JGBs at a yield of 0.110 percent, and it increased the size of its regular buying of five- to 10-year JGBs by 50 billion yen ($439.96 million) to 500 billion yen, Reuters reported.

The BOJ has set a target of keeping the 10-year JGB yield at zero, buying bonds through its quantitative easing program to enforce its policy.

But this week, the 30-year and 40-year JGBs touched their highest yields since February of 2016, while the 10-year touched a five-month high of 0.105 percent, Reuters reported.

A BOJ official said the bank’s increased activity in the market was due to the long-term bonds’ yield rises, Reuters reported.

That came amid a selloff in global bond markets amid expectations that some major central banks, including the U.S. Federal Reserve, the Bank of England and the European Central Bank, were turning more hawkish, and were likely to begin removing some accommodative measures.

Bond yields move inversely to prices.