Sales of non-food items increased 5.1% on the month in April, while fuel sales were up 2.9%, the data showed. However, sales of food, drink and tobacco inched down 0.3% in April compared with the previous month.
The data are adjusted for the number of working days and seasonal factors.
In annual terms, adjusted retail sales advanced 1.2% in April, again supported by higher demand in most sectors, INS data showed.
Non-food sales rose 6.1% on the year in April, while food sales increased by 0.3%. Fuel sales declined 4.8% year-on-year.
In the first four months of 2013, adjusted retail sales were up 1% compared with the year-earlier period, the data showed.
In unadjusted data, retail sales increased 9.2% in April from a month earlier, and were up 2.7% compared with the same period of 2012.