Community Health Systems says data stolen in cyber attack

A photo illustration shows a USB device being plugged into a laptop computer in Berlin July 31, 2014. REUTERS/Thomas Peter

(Reuters) - U.S. hospital operator Community Health Systems Inc said it suspected data of about 4.5 million clients were stolen by Chinese hackers from its computer network. The company and its security contractors Mandiant, a unit of FireEye Inc, believes the attack occurred in April and June, Community Health Systems said in a regulatory filing. (Reporting by Shailesh Kuber; Editing by Joyjeet Das)