WASHINGTON (AP) — Wholesale inflation rose more quickly than expected last month on a big jump in fuel costs, a sign that stubbornly rising prices remain an economic challenge for consumers and a political problem for Republicans in the midterm elections.

The Labor Department’s producer price index — which captures inflation before it reaches consumers — soared 6.3% in September from a year ago, up from 5.6% in August and the biggest increase since December 2022, the government said Thursday.

On a monthly basis, wholesale prices increased 1.3% from August to September, the largest since March 2022, after a 0.5% increase the previous month.

Thursday’s data amplifies the better-known consumer price index, released Wednesday, which also accelerated in September as gas prices jumped. A broad range of goods and services also got more expensive. Both inflation reports raise pressure on the inflation-fighters at the Federal Reserve to hike their key interest rate. Inflation has now topped the central bank’s 2% target for five and a half years.

Excluding the volatile food and energy categories, core prices rose 0.7% from August to September, up sharply from 0.2% in the previous month. Compared with a year ago, core prices rose 5%, up from 4.6% in August.