Consumer prices climbed 2.6% year-on-year in May, slower than April's increase of 2.9%.

Economists had expected inflation to ease slightly to 2.8%. The annual price growth in utilities eased to 3.1% in May from 3.3% a month ago.

Transportation costs rose at a faster rate of 5.3%, while costs for food and alcoholic beverages continued to fall by 3.7%.

On a monthly comparison basis, consumer prices remained flat in May, versus a 0.7% increase in April.