Sweden's inflation rose 7.2% in May, marking its highest annual gain in almost 31 years, according to official figures released Tuesday.

This is the highest inflation rate according to the consumer price index with a fixed interest rate (CPIF) since December 1991, Statistics Sweden said in a statement.

While the market estimate for the CPIF was an annual gain of 7%, the figure rose 6.4% in April, from the same period of last year.

On a monthly basis, the inflation rate according to the CPIF rose 1% in May, from the previous month.

"The monthly change in May was mainly driven by price increases in food and non-alcoholic beverages," the statement said. "In addition to food prices, electricity and recreation and culture contributed to the monthly increase."

It added that the inflation rate according to CPIF excluding energy increased 5.4% in May on an annual basis.

The CPIF shows the same price trend as the consumer price index, but without the direct effects of a changed monetary policy, according to Statistics Sweden./aa