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.

The BOJ’s announced bond purchase plans bashed the yen, with the dollar fetching as much as 113.83 yen, compared with as low as 113.07 yen earlier in the session.

The dollar/yen pair was at 113.71 at 10:50 a.m. HK/SIN.

The dollar index, which measures the greenback against a basket of currencies, also climbed, rising as high as 95.965, from as low as 95.811. The index was at 95.950 at 10:52 a.m. HK/SIN.

That likely had a knock-on effect on oil, which is priced in dollars.

U.S. light crude futures for August touched a low of $44.64 a barrel, amid the currency moves, trading off a high of $45.42 earlier in the session. The futures were down 1.23 percent at $44.96 a barrel at 10:54 a.m. HK/SIN.

Brent futures for September also fell as low as $47.24 a barrel, from as high as $45.42. The Brent futures were trading down 1.23 percent at $47.52 at 10:57 a.m. HK/SIN.