Chinese police last month detained four people suspected of trying to obtain consumer data from e-commerce site 360buy.com, which is operated by Beijing Jingdong Century Trading Co.

WSJ: Chinese Online Retailer Yihaodian Probes Possible Security Breach

Although Amazon has run an e-commerce operation in China for years, it has failed to build up a significant market share as local competitors such as Alibaba Group Holdings Ltd. and Beijing Jingdong Century Trading Co. have pressed to attract new customers.

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That could make it difficult for the chain to differentiate itself from other online rivals in the already crowded space in China, where it would have to compete with the likes of global names Walmart (NYSE: WMT) and local giants like Jingdong .

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