Japan Jumps Into Market to Buy Yen for First Time in 24 Years; Currency Rallies

TOKYO—Japan intervened in the foreign exchange market by buying yen for the first time in 24 years, shortly after the Bank of Japan accelerated a fall in the currency by confirming it would maintain ultralow interest rates.

The rare intervention was the latest example of global concern triggered by the strong dollar, which has gained ground on the back of the Federal Reserve’s interest-rate increases.