BEIJING--Chinese online travel company Ctrip.com International Ltd. said Thursday that some of its servers had been hacked, causing disruptions to its website and mobile app services.

The Nasdaq-traded company said it suspected that some of its servers had been attacked by "unidentified sources," but that its customer data remained intact.

In a statement on its verified Weibo microblog account several hours after the disruption began, the Shanghai-based company said that that it was still investigating the cause of the problem and trying to restore service.

U.S.-based Priceline Group Inc. said this week it planned to increase its investment in the Chinese company, investing $250 million through a convertible bond after making a $500 million investment last summer. That could ultimately give Priceline about 10.5% of Ctrip's outstanding shares.

--Liyan Qi

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