In April, adjusted retail sales increased 2% compared with the previous month. The data are adjusted for the number of working days and seasonal factors.
Fuel sales declined 6.6% on the month in May, while sales of non-food items were down 6%, the data showed. However, sales of food, drink and tobacco inched up 0.9% in May from a month earlier.
In annual terms, adjusted retail sales fell 3.3% in May, again due to falling demand in most sectors, INS data showed.
Fuel sales dropped 11.9% on the year in May, while non-food sales edged down 0.1%. Food sales advanced 0.3% year-on-year.
In the first five months of 2013, adjusted retail sales were roughly unchanged compared with the year-earlier period, the data showed.
In unadjusted data, retail sales decreased 2.7% in May from a month earlier, and were down 4.4% compared with the same period of 2012.