Retail gasoline prices in Japan rose to their highest levels this week since April 1997 as oil distributors passed on recent increases in wholesale prices triggered by higher crude prices, an industry group said Wednesday.

The average price of regular gasoline at the pump on Monday stood at 112 yen per liter, up 4 yen from a week earlier, the Oil Information Center said.

The price matches that logged April 14, 1997, when the retail price of gasoline rose due to a consumption tax increase, the research center said.

Last month, major oil refiners raised their wholesale gasoline prices by about 4 yen per liter, effective with June shipments, to try to cover an increase in their crude oil procurement costs.

The average price of high-octane premium gasoline increased 4 yen per liter to 124 yen Monday, the center said.

The average price of diesel oil increased 2 yen per liter to 88 yen, and that of kerosene rose 36 yen per 18-liter can to 904 yen, the center said.