Non-food sales increased 3.8% on the month in May, while fuel prices were up 3.4%. On the other hand, food sales declined 1% month-on-month.
The data are adjusted for the number of working days and seasonal factors.
In annual terms, adjusted retail sales rose 10.1% in May, helped by higher demand in all sectors, INS data showed.
Non-food sales increased 16.6% on the year in May, while food and fuel sales advanced 6.6% and 3.6%, respectively.
In the first five months of 2014, adjusted retail sales were up 7.8% compared with the year-earlier period, again boosted by growing demand across the board.
In unadjusted data, retail sales increased 1.7% in May from a month earlier, and were up 9.2% compared with the same period of 2013.