Chinese e-commerce retailer Yihaodian said it is investigating a possible security breach, potentially the latest in a growing number of attempts to pilfer online consumer information, The Wall Street Journal reported. The firm said it was working with local public security officials to probe the incident but did not give any further information on the nature of the attack or how many of its 18 million registered users might have been affected. Yihaodian is partly owned by Wal-Mart (WMT.NYSE); in February the US retailer said it plans to increase its investment in the Chinese company to 51% from 18%, pending regulatory approval. Experts say hacking efforts increasingly focus on China’s rapidly growing e-commerce industry. Last month, Chinese police detained four people in connection with an attempt to steal consumer data from e-commerce retailer 360buy.com.