South Korea's producer price index (PPI) — a key measure of upstream inflationary pressure — rose 1.6 percent month-on-month in March, the sharpest increase since April 2022, according to data released Wednesday by the Bank of Korea. The surge was driven primarily by a 31.9 percent jump in coal and petroleum product prices, along with a 6.7 percent rise in chemical goods, as conflict in the Middle East following US-Israeli strikes on Iran has disrupted global oil supplies. The data raises concern about future consumer inflation, as producer prices typically feed through to retail costs in the months ahead.