Inflation in Tokyo accelerated for a fourth consecutive month to rise at the fastest pace since 1992 excluding the impact of tax hikes, and adding to the challenges for the Bank of Japan in communicating its need for inflation-supporting easing.

Consumer prices excluding fresh food rose 2.8% in the capital in September from a year earlier, according to the ministry of internal affairs Tuesday. The gain matched economist forecasts.

The growth in Tokyo prices was led by gains in processed food and durable goods, with the former jumping the most in 41 years. Energy’s impact on prices was slightly less compared to the previous month.