Convenience store sales in March increased 4.2 percent from a year earlier to ¥613.40 billion on a same-store basis, up for the 11th straight month, the Japan Franchise Association said Monday.

Sales were again boosted by people buying cigarettes at convenience stores, which has helped to lift sales over the past several months, the association said.

Last July saw the introduction of taspo smart cards, which are designed to prevent minors from buying cigarettes from vending machines. However, many smokers have not applied for the age-identification cards and are instead buying cigarettes at convenience stores.

The number of people visiting convenience stores stood at 1.048 million, up 5.0 percent from a year earlier and rising for the 12th consecutive month. However, average spending per customer fell for the fourth straight month to ¥585.4, down 0.7 percent from the year before.